Method of cultivating plants without using soil but by using nutrient solution? ?->(Show Answer!)

1. Method of cultivating plants without using soil but by using nutrient solution?

Answer: Hydroponics

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MCQ-> Modern science, exclusive of geometry, is a comparatively recent creation and can be said to have originated with Galileo and Newton. Galileo was the first scientist to recognize clearly that the only way to further our understanding of the physical world was to resort to experiment. However obvious Galileo’s contention may appear in the light of our present knowledge, it remains a fact that the Greeks, in spite of their proficiency in geometry, never seem to have realized the importance of experiment. To a certain extent this may be attributed to the crudeness of their instruments of measurement. Still an excuse of this sort can scarcely be put forward when the elementary nature of Galileo’s experiments and observations is recalled. Watching a lamp oscillate in the cathedral of Pisa, dropping bodies from the leaning tower of Pisa, rolling balls down inclined planes, noticing the magnifying effect of water in a spherical glass vase, such was the nature of Galileo’s experiments and observations. As can be seen, they might just as well have been performed by the Greeks. At any rate, it was thanks to such experiments that Galileo discovered the fundamental law of dynamics, according to which the acceleration imparted to a body is proportional to the force acting upon it.The next advance was due to Newton, the greatest scientist of all time if account be taken of his joint contributions to mathematics and physics. As a physicist, he was of course an ardent adherent of the empirical method, but his greatest title to fame lies in another direction. Prior to Newton, mathematics, chiefly in the form of geometry, had been studied as a fine art without any view to its physical applications other than in very trivial cases. But with Newton all the resources of mathematics were turned to advantage in the solution of physical problems. Thenceforth mathematics appeared as an instrument of discovery, the most powerful one known to man, multiplying the power of thought just as in the mechanical domain the lever multiplied our physical action. It is this application of mathematics to the solution of physical problems, this combination of two separate fields of investigation, which constitutes the essential characteristic of the Newtonian method. Thus problems of physics were metamorphosed into problems of mathematics.But in Newton’s day the mathematical instrument was still in a very backward state of development. In this field again Newton showed the mark of genius by inventing the integral calculus. As a result of this remarkable discovery, problems, which would have baffled Archimedes, were solved with ease. We know that in Newton’s hands this new departure in scientific method led to the discovery of the law of gravitation. But here again the real significance of Newton’s achievement lay not so much in the exact quantitative formulation of the law of attraction, as in his having established the presence of law and order at least in one important realm of nature, namely, in the motions of heavenly bodies. Nature thus exhibited rationality and was not mere blind chaos and uncertainty. To be sure, Newton’s investigations had been concerned with but a small group of natural phenomena, but it appeared unlikely that this mathematical law and order should turn out to be restricted to certain special phenomena; and the feeling was general that all the physical processes of nature would prove to be unfolding themselves according to rigorous mathematical laws.When Einstein, in 1905, published his celebrated paper on the electrodynamics of moving bodies, he remarked that the difficulties, which surrouned the equations of electrodynamics, together with the negative experiments of Michelson and others, would be obviated if we extended the validity of the Newtonian principle of the relativity of Galilean motion, which applies solely to mechanical phenomena, so as to include all manner of phenomena: electrodynamics, optical etc. When extended in this way the Newtonian principle of relativity became Einstein’s special principle of relativity. Its significance lay in its assertion that absolute Galilean motion or absolute velocity must ever escape all experimental detection. Henceforth absolute velocity should be conceived of as physically meaningless, not only in the particular ream of mechanics, as in Newton’s day, but in the entire realm of physical phenomena. Einstein’s special principle, by adding increased emphasis to this relativity of velocity, making absolute velocity metaphysically meaningless, created a still more profound distinction between velocity and accelerated or rotational motion. This latter type of motion remained absolute and real as before. It is most important to understand this point and to realize that Einstein’s special principle is merely an extension of the validity of the classical Newtonian principle to all classes of phenomena.According to the author, why did the Greeks NOT conduct experiments to understand the physical world?
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MCQ-> I want to stress this personal helplessness we are all stricken with in the face of a system that has passed beyond our knowledge and control. To bring it nearer home, I propose that we switch off from the big things like empires and their wars to more familiar little things. Take pins for example! I do not know why it is that I so seldom use a pin when my wife cannot get on without boxes of them at hand; but it is so; and I will therefore take pins as being for some reason specially important to women.There was a time when pinmakers would buy the material; shape it; make the head and the point; ornament it; and take it to the market, and sell it and the making required skill in several operations. They not only knew how the thing was done from beginning to end, but could do it all by themselves. But they could not afford to sell you a paper of pins for the farthing. Pins cost so much that a woman's dress allowance was calling pin money.By the end of the 18th century Adam Smith boasted that it took 18 men to make a pin, each man doing a little bit of the job and passing the pin on to the next, and none of them being able to make a whole pin or to buy the materials or to sell it when it was made. The most you could say for them was that at least they had some idea of how it was made, though they could not make it. Now as this meant that they were clearly less capable and knowledgeable men than the old pin-makers, you may ask why Adam Smith boasted of it as a triumph of civilisation when its effect had so clearly a degrading effect. The reason was that by setting each man to do just one little bit of the work and nothing but that, over and over again, he became very quick at it. The men, it is said, could turn out nearly 5000 pins a day each; and thus pins became plentiful and cheap. The country was supposed to be richer because it had more pins, though it had turned capable men into mere machines doing their work without intelligence and being fed by the spare food of the capitalist just as an engine is fed with coals and oil. That was why the poet Goldsmith, who was a farsighted economist as well as a poet, complained that 'wealth accumulates, and men decay'.Nowadays Adam Smith's 18 men are as extinct as the diplodocus. The 18 flesh-and-blood men have been replaced by machines of steel which spout out pins by the hundred million. Even sticking them into pink papers is done by machinery. The result is that with the exception of a few people who design the machines, nobody knows how to make a pin or how a pin is made: that is to say, the modern worker in pin manufacture need not be one-tenth so intelligent, skilful and accomplished as the old pinmaker; and the only compensation we have for this deterioration is that pins are so cheap that a single pin has no expressible value at all. Even with a big profit stuck on to the cost-price you can buy dozens for a farthing; and pins are so recklessly thrown away and wasted that verses have to be written to persuade children (without success) that it is a sin to steal, if even it’s a pin.Many serious thinkers, like John Ruskin and William Morris, have been greatly troubled by this, just as Goldsmith was, and have asked whether we really believe that it is an advance in wealth to lose our skill and degrade our workers for the sake of being able to waste pins by the ton. We shall see later on, when we come to consider the Distribution of Leisure, that the cure for this is not to go back to the old free for higher work than pin-making or the like. But in the meantime the fact remains that the workers are now not able to make anything themselves even in little bits. They are ignorant and helpless, and cannot lift their finger to begin their day's work until it has all been arranged for them by their employer's who themselves do not understand the machines they buy, and simply pay other people to set them going by carrying out the machine maker's directions.The same is true for clothes. Earlier the whole work of making clothes, from the shearing of the sheep to the turning out of the finished and washed garment ready to put on, had to be done in the country by the men and women of the household, especially the women; so that to this day an unmarried woman is called a spinster. Nowadays nothing is left of all this but the sheep shearing; and even that, like the milking of cows, is being done by machinery, as the sewing is. Give a woman a sheep today and ask her to produce a woollen dress for you; and not only will she be quite unable to do it, but you are likely to find that she is not even aware of any connection between sheep and clothes. When she gets her clothes, which she does by buying them at the shop, she knows that there is a difference between wool and cotton and silk, between flannel and merino, perhaps even between stockinet and other wefts; but as to how they are made, or what they are made of, or how they came to be in the shop ready for her to buy, she knows hardly anything. And the shop assistant from whom she buys is no wiser. The people engaged in the making of them know even less; for many of them are too poor to have much choice of materials when they buy their own clothes.Thus the capitalist system has produced an almost universal ignorance of how things are made and done, whilst at the same time it has caused them to be made and done on a gigantic scale. We have to buy books and encyclopaedias to find out what it is we are doing all day; and as the books are written by people who are not doing it, and who get their information from other books, what they tell us is twenty to fifty years out of date knowledge and almost impractical today. And of course most of us are too tired of our work when we come home to want to read about it; what we need is cinema to take our minds off it and feel our imagination.It is a funny place, this word of capitalism, with its astonishing spread of education and enlightenment. There stand the thousands of property owners and the millions of wage workers, none of them able to make anything, none of them knowing what to do until somebody tells them, none of them having the least notion of how it is made that they find people paying them money, and things in the shops to buy with it. And when they travel they are surprised to find that savages and Esquimaux and villagers who have to make everything for themselves are more intelligent and resourceful! The wonder would be if they were anything else. We should die of idiocy through disuse of our mental faculties if we did not fill our heads with romantic nonsense out of illustrated newspapers and novels and plays and films. Such stuff keeps us alive, but it falsifies everything for us so absurdly that it leaves us more or less dangerous lunatics in the real world.Excuse my going on like this; but as I am a writer of books and plays myself, I know the folly and peril of it better than you do. And when I see that this moment of our utmost ignorance and helplessness, delusion and folly, has been stumbled on by the blind forces of capitalism as the moment for giving votes to everybody, so that the few wise women are hopelessly overruled by the thousands whose political minds, as far as they can be said to have any political minds at all, have been formed in the cinema, I realise that I had better stop writing plays for a while to discuss political and social realities in this book with those who are intelligent enough to listen to me.A suitable title to the passage would be
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MCQ-> Read the following passage carefully and answer the questions given at the end.The movement to expel the Austrians from Italy and unite Italy under a republican government had been gaining momentum while Garibaldi was away. There was a growing clamour, not just from Giuseppe Mazzini's republicans, but from moderates as well, for a General capable of leading Italy to independence. Even the King of Piedmont, for whom Garibaldi was still an outlaw under sentence of death, subscribed to an appeal for a sword for the returning hero. Meanwhile, the 'year of revolutions', 1848, had occurred in which Louis Philippe had been toppled from the French throne. In Austria, an uprising triggered off insurrections in Venice and Milan, and the Austrian garrisons were forced out. The King of Piedmont, Charles Albert ordered his troops to occupy these cities. There had also been insurrections in Sicily, causing the King Ferdinand II, to grant major constitutional freedoms in 1849, prompting both the Pope and Charles Albert to grant further concessions.Meanwhile, largely ignorant of these developments, Garibaldi was approaching Italy at a leisurely pace, arriving at Nice on 23 June 1848 to a tumultuous reception. The hero declared himself willing to fight and lay down his life for Charles Albert, who he now regarded as a bastion of Italian nationalism.Mazzini and the republicans were horrified, regarding this as outright betrayal: did it reflect Garibaldi's innate simple-mindedness, his patriotism in the war against Austria, or was it part of a deal with the monarchy? Charles Albert had pardoned Garibaldi, but to outward appearances he was still very wary of the General and the Italian Legion he had amassed of 150 'brigands'. The two men met near Mantua, and the King appeared to dislike him instantly. He suggested that Garibaldi's men should join his army and that Garibaldi should go to Venice and captain a ship as a privateer against the Austrians.Garibaldi, meanwhile, met his former hero Mazzini for the first time, and again the encounter was frosty. Seemingly rebuffed on all sides, Garibaldi considered going to Sicily to fight King Ferdinand II of Naples, but changed his mind when the Milanese offered him the post of General - something they badly needed when Charles Albert's Piedmontese army was defeated at Custoza by the Austrians. With around 1,000 men, Garibaldi marched into the mountains at Varese, commenting bitterly: 'The King of Sardinia may have a crown that he holds on to by dint of misdeeds and cowardice, but my comrades and I do not wish to hold on to our lives by shameful actions'.The King of Piedmont offered an armistice to the Austrians and all the gains in northern Italy were lost again. Garibaldi returned to Nice and then across to Genoa, where he learned that, in September 1848, Ferdinand II had bombed Messina as a prelude to invasion - an atrocity which caused him to be dubbed 'King Bomba'. Reaching Livorno he was diverted yet again and set off across the Italian peninsula with 350 men to come to Venice's assistance, but on the way, in Bologna, he learned that the Pope had taken refuge with King Bomba. Garibaldi promptly altered course southwards towards Rome where he was greeted once again as a hero. Rome proclaimed itself a Republic. Garibaldi's Legion had swollen to nearly 1,300 men, and the Grand Duke of Tuscany fled Florence before the advancing republican force.However, the Austrians marched southwards to place the Grand Duke of Tuscany back on his throne. Prince Louis Napoleon of France despatched an army of 7,000 men under General Charles Oudinot to the port of Civitavecchia to seize the city. Garibaldi was appointed as a General to defend Rome.The republicans had around 9,000 men, and Garibaldi was given control of more than 4,000 to defend the Janiculum Hill, which was crucial to the defence of Rome, as it commanded the city over the Tiber. Some 5,000 well-equipped French troops arrived on 30 April 1849 at Porta Cavallegeri in the old walls of Rome, but tailed to get through, and were attacked from behind by Garibaldi, who led a baton charge and was grazed by a bullet slightly on his side. The French lost 500 dead and wounded, along with some 350 prisoners, to the Italians, 200 dead and wounded. It was a famous victory, wildly celebrated by the Romans into the night, and the French signed a tactical truce.However, other armies were on the march: Bomba's 12,500-strong Neapolitan army was approaching from the south, while the Austrians had attacked Bologna in the north. Garibaldi too, a force out of Rome and engaged in a flanking movement across the Neapolitan army's rear at Castelli Romani; the Neapolitans attacked and were driven off leaving 50 dead. Garibaldi accompanied the Roman General, Piero Roselli, in an attack on the retreating Neapolitan army. Foolishly leading a patrol of his men right out in front of his forces, he tried to stop a group of his cavalry retreating and fell under their horses, with the enemy slashing at him with their sabres. He was rescued by his legionnaires, narrowly having avoided being killed, but Roselli had missed the chance to encircle the Neapolitan army.Garibaldi boldly wanted to carry the fight down into the Kingdom of Naples, but Mazzini, who by now was effectively in charge of Rome, ordered him back to the capital to face the danger of Austrian attack from the north. In fact, it was the French who arrived on the outskirts of Rome first, with an army now reinforced by 30,000. Mazzini realized that Rome could not resist and ordered a symbolic stand within the city itself, rather than surrender, for the purposes of international propaganda and to keep the struggle alive, whatever the cost. On 3 June the French arrived in force and seized the strategic country house, Villa Pamphili.Garibaldi rallied his forces and fought feverishly to retake the villa up narrow and steep city streets, capturing it, then losing it again. By the end of the day, the sides had 1,000 dead between them. Garibaldi once again had been in the thick of the fray, giving orders to his troops and - fighting, it was said, like a lion. Although beaten 'off for the moment, the French imposed a siege in the morning, starving the city of provisions and bombarding its beautiful centre.On 30 June the French attacked again in force, while Garibaldi, at the head of his troops, fought back ferociously. But there was no prospect of holding the French off indefinitely, and Garibaldi, decided to take his men out of the city to continue resistance in the mountains. Mazzini fled to Britain while Garibaldi remained to fight for the cause. He had just 4,000 men, divided into two legions, and faced some 17,000 Austrians and Tuscans in the north, 30,000 Neapolitans and Spanish in the south, and 40,000 French in the west. He was being directly pursued by 8,000 French and was approaching Neapolitan and Spanish divisions of some 18,000 men. He stood no chance whatever. The rugged hill country was ideal, however, for his style of irregular guerrilla warfare, and he manoeuvred skilfully, marching and counter-marching in different directions, confounding his pursuers before finally aiming for Arezzo in the north. But his men were deserting in droves and local people were hostile to his army: he was soon reduced to 1500 men who struggled across the high mountain passes to San Marino where he found temporary. refuge.The Austrians, now approaching, demanded that he go into exile in America. He was determined to fight on and urged the ill and pregnant Anita, his wife, to stay behind in San Marino, but she would not hear of it. The pair set off with 200 loyal soldiers along the mountain tracks to the Adriatic coast, from where Garibaldi intended to embark for Venice which was still valiantly holding out against the Austrians. They embarked aboard 13 fishing boats and managed to sail to within 50 miles of the Venetian lagoon before being spotted by an Austrian flotilla and fired upon.Only two of Garibaldi's boats escaped. He carried Anita through the shallows to a beach and they moved further inland. The ailing Anita was placed in a cart and they reached a farmhouse, where she died. Her husband broke down into inconsolable wailing and she was buried in a shallow grave near the farmhouse, but was transferred to a churchyard a few days later. Garibaldi had no time to lose; he and his faithful companion Leggero escaped across the Po towards Ravenna.At last Garibaldi was persuaded to abandon his insane attempts to reach Venice by sea and to return along less guarded routes on the perilous mountain paths across the Apennines towards the western coast of Italy. He visited his family in Nice for an emotional reunion with his mother and his three children - but lacked the courage to tell them what had happened to their mother.Find the correct statement:
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MCQ-> Some psychologists and sociologists believe that psychopathy can be an asset in business and politics and that, as a result, psychopathic traits are overrepresented among successful people. This would be a puzzle if it were so. If our moral feelings evolved through natural selection, then it shouldn‘t be the case that one would flourish without them. And, in fact, the successful psychopath is probably the exception. Psychopaths have certain deficits. Some of these are subtle. The psychologist Abigail Marsh and her colleagues find that psychopaths are markedly insensitive to the expression of fear. Normal people recognize fear and treat it as a distress cue, but 13 psychopaths have problems seeing it, let alone responding to it appropriately. Other deficits run deeper. The overall lack of moral sentiments—and specifically, the lack of regard for others—might turn out to be the psychopath‘s downfall. We non-psychopaths are constantly assessing one another, looking for kindness and shame and the like, using this information to decide whom to trust, whom to affiliate with. The psychopath has to pretend to be one of us. But this is difficult. It‘s hard to force yourself to comply with moral rules just through a rational appreciation of what you are expected to do. If you feel like strangling the cat, it‘s a struggle to hold back just because you know that it is frowned upon. Without a normal allotment of shame and guilt, psychopaths succumb to bad impulses, doing terrible things out of malice, greed, and simple boredom. And sooner or later, they get caught. While psychopaths can be successful in the short term, they tend to fail in the long term and often end up in prison or worse. Let‘s take a closer look at what separates psychopaths from the rest of us. There are many symptoms of psychopathy, including pathological lying and lack of remorse or guilt, but the core deficit is indifference toward the suffering of other people. Psychopaths lack compassion. To understand how compassion works for all of us non-psychopaths, it‘s important to distinguish it from empathy. Now, some contemporary researchers use the terms interchangeably, but there is a big difference between caring about a person (compassion) and putting yourself in the person‘s shoes (empathy).I am too much of an adaptationist to think that a capacity as rich as empathy exists as a freak biological accident. It most likely has a function, and the most plausible candidate here is that it motivates us to care about others. Empathy exists to motivate compassion and altruism. Still, the link between empathy (in the sense of mirroring another‘s feelings) and compassion (in the sense of feeling and acting kindly toward another) is more nuanced than many people believe. First, although empathy can be automatic and unconscious—a crying person can affect your mood, even if you‘re not aware that this is happening and would rather it didn‘t—we often choose whether to empathize with another person. So when empathy is present, it may be the product of a moral choice, not the cause of it. Empathy is also influenced by what one thinks of the other person. Second, empathy is not needed to motivate compassion. As the psychologist Steven Pinker points out, “If a child has been frightened by a barking dog and is howling in terror, my sympathetic response is not to howl in terror with her, but to comfort and protect her” Third, just as you can have compassion without empathy, you can have empathy without compassion. You might feel the person‘s pain and wish to stop feeling it—but choose to solve the problem by distancing yourself from that person instead of alleviating his or her suffering. Even otherwise good people sometimes turn away when faced with depictions of pain and suffering in faraway lands, or when passing a homeless person on a city street.The core deficit of Psychopaths affects their long term success because,
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MCQ-> The broad scientific understanding today is that our planet is experiencing a warming trend over and above natural and normal variations that is almost certainly due to human activities associated with large-scale manufacturing. The process began in the late 1700s with the Industrial Revolution, when manual labor, horsepower, and water power began to be replaced by or enhanced by machines. This revolution, over time, shifted Britain, Europe, and eventually North America from largely agricultural and trading societies to manufacturing ones, relying on machinery and engines rather than tools and animals.The Industrial Revolution was at heart a revolution in the use of energy and power. Its beginning is usually dated to the advent of the steam engine, which was based on the conversion of chemical energy in wood or coal to thermal energy and then to mechanical work primarily the powering of industrial machinery and steam locomotives. Coal eventually supplanted wood because, pound for pound, coal contains twice as much energy as wood (measured in BTUs, or British thermal units, per pound) and because its use helped to save what was left of the world's temperate forests. Coal was used to produce heat that went directly into industrial processes, including metallurgy, and to warm buildings, as well as to power steam engines. When crude oil came along in the mid- 1800s, still a couple of decades before electricity, it was burned, in the form of kerosene, in lamps to make light replacing whale oil. It was also used to provide heat for buildings and in manufacturing processes, and as a fuel for engines used in industry and propulsion.In short, one can say that the main forms in which humans need and use energy are for light, heat, mechanical work and motive power, and electricity which can be used to provide any of the other three, as well as to do things that none of those three can do, such as electronic communications and information processing. Since the Industrial Revolution, all these energy functions have been powered primarily, but not exclusively, by fossil fuels that emit carbon dioxide (CO2), To put it another way, the Industrial Revolution gave a whole new prominence to what Rochelle Lefkowitz, president of Pro-Media Communications and an energy buff, calls "fuels from hell" - coal, oil, and natural gas. All these fuels from hell come from underground, are exhaustible, and emit CO2 and other pollutants when they are burned for transportation, heating, and industrial use. These fuels are in contrast to what Lefkowitz calls "fuels from heaven" -wind, hydroelectric, tidal, biomass, and solar power. These all come from above ground, are endlessly renewable, and produce no harmful emissions.Meanwhile, industrialization promoted urbanization, and urbanization eventually gave birth to suburbanization. This trend, which was repeated across America, nurtured the development of the American car culture, the building of a national highway system, and a mushrooming of suburbs around American cities, which rewove the fabric of American life. Many other developed and developing countries followed the American model, with all its upsides and downsides. The result is that today we have suburbs and ribbons of highways that run in, out, and around not only America s major cities, but China's, India's, and South America's as well. And as these urban areas attract more people, the sprawl extends in every direction.All the coal, oil, and natural gas inputs for this new economic model seemed relatively cheap, relatively inexhaustible, and relatively harmless-or at least relatively easy to clean up afterward. So there wasn't much to stop the juggernaut of more people and more development and more concrete and more buildings and more cars and more coal, oil, and gas needed to build and power them. Summing it all up, Andy Karsner, the Department of Energy's assistant secretary for energy efficiency and renewable energy, once said to me: "We built a really inefficient environment with the greatest efficiency ever known to man."Beginning in the second half of the twentieth century, a scientific understanding began to emerge that an excessive accumulation of largely invisible pollutants-called greenhouse gases - was affecting the climate. The buildup of these greenhouse gases had been under way since the start of the Industrial Revolution in a place we could not see and in a form we could not touch or smell. These greenhouse gases, primarily carbon dioxide emitted from human industrial, residential, and transportation sources, were not piling up along roadsides or in rivers, in cans or empty bottles, but, rather, above our heads, in the earth's atmosphere. If the earth's atmosphere was like a blanket that helped to regulate the planet's temperature, the CO2 buildup was having the effect of thickening that blanket and making the globe warmer.Those bags of CO2 from our cars float up and stay in the atmosphere, along with bags of CO2 from power plants burning coal, oil, and gas, and bags of CO2 released from the burning and clearing of forests, which releases all the carbon stored in trees, plants, and soil. In fact, many people don't realize that deforestation in places like Indonesia and Brazil is responsible for more CO2 than all the world's cars, trucks, planes, ships, and trains combined - that is, about 20 percent of all global emissions. And when we're not tossing bags of carbon dioxide into the atmosphere, we're throwing up other greenhouse gases, like methane (CH4) released from rice farming, petroleum drilling, coal mining, animal defecation, solid waste landfill sites, and yes, even from cattle belching. Cattle belching? That's right-the striking thing about greenhouse gases is the diversity of sources that emit them. A herd of cattle belching can be worse than a highway full of Hummers. Livestock gas is very high in methane, which, like CO2, is colorless and odorless. And like CO2, methane is one of those greenhouse gases that, once released into the atmosphere, also absorb heat radiating from the earth's surface. "Molecule for molecule, methane's heat-trapping power in the atmosphere is twenty-one times stronger than carbon dioxide, the most abundant greenhouse gas.." reported Science World (January 21, 2002). “With 1.3 billion cows belching almost constantly around the world (100 million in the United States alone), it's no surprise that methane released by livestock is one of the chief global sources of the gas, according to the U.S. Environmental Protection Agency ... 'It's part of their normal digestion process,' says Tom Wirth of the EPA. 'When they chew their cud, they regurgitate [spit up] some food to rechew it, and all this gas comes out.' The average cow expels 600 liters of methane a day, climate researchers report." What is the precise scientific relationship between these expanded greenhouse gas emissions and global warming? Experts at the Pew Center on Climate Change offer a handy summary in their report "Climate Change 101. " Global average temperatures, notes the Pew study, "have experienced natural shifts throughout human history. For example; the climate of the Northern Hemisphere varied from a relatively warm period between the eleventh and fifteenth centuries to a period of cooler temperatures between the seventeenth century and the middle of the nineteenth century. However, scientists studying the rapid rise in global temperatures during the late twentieth century say that natural variability cannot account for what is happening now." The new factor is the human factor-our vastly increased emissions of carbon dioxide and other greenhouse gases from the burning of fossil fuels such as coal and oil as well as from deforestation, large-scale cattle-grazing, agriculture, and industrialization.“Scientists refer to what has been happening in the earth’s atmosphere over the past century as the ‘enhanced greenhouse effect’”, notes the Pew study. By pumping man- made greenhouse gases into the atmosphere, humans are altering the process by which naturally occurring greenhouse gases, because of their unique molecular structure, trap the sun’s heat near the earth’s surface before that heat radiates back into space."The greenhouse effect keeps the earth warm and habitable; without it, the earth's surface would be about 60 degrees Fahrenheit colder on average. Since the average temperature of the earth is about 45 degrees Fahrenheit, the natural greenhouse effect is clearly a good thing. But the enhanced greenhouse effect means even more of the sun's heat is trapped, causing global temperatures to rise. Among the many scientific studies providing clear evidence that an enhanced greenhouse effect is under way was a 2005 report from NASA's Goddard Institute for Space Studies. Using satellites, data from buoys, and computer models to study the earth's oceans, scientists concluded that more energy is being absorbed from the sun than is emitted back to space, throwing the earth's energy out of balance and warming the globe."Which of the following statements is correct? (I) Greenhouse gases are responsible for global warming. They should be eliminated to save the planet (II) CO2 is the most dangerous of the greenhouse gases. Reduction in the release of CO2 would surely bring down the temperature (III) The greenhouse effect could be traced back to the industrial revolution. But the current development and the patterns of life have enhanced their emissions (IV) Deforestation has been one of the biggest factors contributing to the emission of greenhouse gases Choose the correct option:...