题目内容
2 Climatic conditions are delicately adjusted to the composition of the Earth’s atmos phere. If there were a change in the atmosphere—for example, in the relative proportions of atmosphere gases—the climate would probably change also. A slight increase in water vapor, for instance, would increase the hem-retaining capacity of the atmosphere and would lead to a rise in global temperatures. In contrast, a large increase in water vapor would increase the thickness and extent of the cloud layer, reducing the mount of solar en ergy reaching the Earth’surface. The level of carbon dioxide, CO2 in the atmosphere has important effect on climatic change. Most of the Earth’s incoming energy is short-wavelength radiation, which tends to pass through atmospheric CO2 easily. The Earth, however, reradiates much of the re ceived energy as a long-wavelength radiation, which CO2 absorbs and then remits toward the Earth. This phenomenon, known as the greenhouse effect, can result in an increase in the surface temperature of a planet. An extreme example of the effect is shown by the Ve- nus, a planet covered by heavy clouds composed mostly of CO2, whose surface tempera tures have been measured at 43℃. If the CO2 content of the atmosphere is reduced, the temperature falls. According to one respectable theory, if the atmospheric CO2 concentra tion were halved, the Earth would become completely covered with ice. Another equally respectable theory, however, states that a halving of the CO2 concentration would lead only to a reduction in global temperatures of 3℃. If, because of an increase in forest fires or volcanic activity, the CO2 content of the atmosphere increased, a warmer climate would be produced. Plant growth, which relies on both the warmth and the availability of CO2, would probably increase. As a consequence, plants would use more and more CO2，Eventually CO2 levels would diminish and the cli mate, in turn, would become cooler. With reduced temperatures many plants would die; CO2 would thereby be returned to the atmosphere and gradually the temperatures would rise again. Thus, if this process occurred, there might be a long-term oscillation in the amount of CO2 present in the atmosphere, with regular temperature increase and decrease of a set magnitude. Some climatologists argue that the burning of fossil fuels has raised the level of CO2 in the atmosphere and has caused a global temperature rise of at least 1℃. But a supposed global temperature rise of 1℃ may in reality be only several regional temperature increase, restricted to areas where there are many meteorological stations and caused simply by shifts in the pattern of atmospheric circulation. Other areas, for example the Southern Hemi sphere oceanic zone, may be experiencing an equivalent temperature decrease that is unrec ognized because of the shortage of meteorological recording stations. The author is primarily concentrated on______.
查看答案
搜索结果不匹配？点我反馈
更多问题
首先考虑的疾病是：
[听力原文]W: Why didn’t your aunt fly to New YorkM: It would have cost $140. The bus fare is only $ 40. How much did the man’s aunt save（）
4 Next to Sir Andrew in the club-room sits Captain Sentry, a gentleman of great cour age, good understanding, but invincible modesty. He is one of those that deserve very well, but are very awkward at putting their talents within the observation of such as should take notice of them. He was some years a captain, and behaved himself with great gallantry in several engagements and at several sieges; but having a small estate of his own, and being next heir to Sir Roger, he has quitted a way of life in which no man can rise suitably to his merit, who is not something of a courtier as well as a soldier. I have heard him often lament that in a profession where merit is placed in so conspicuous a view, impudence should get the better of modesty. When he had talked to this purpose; I never heard him make a sour expression, but frankly confess that he left the world because he was not fit for it. A strict honesty, and an even regular behavior, are in themselves obsta cles to him that must press through crowds, who endeavour at the same end with himself, the favor of a commander. He will, however, in his way of talk excuse generals for not disposing according to men’s desert, or inquiring into it; for, says he, that the great man who has a mind to help me, has as many, to break through to come at me, as I have to come at him: therefore he will conclude that the man who would make a figure, especially in a military way, must get over all false modesty, and assist his patron against the impor tunity of other pretenders, by a proper assurance in his own vindication. He says it is a civil cowardice to be backward in asserting what you ought to expect, as it is a military fear to be slow in attacking when it is your duty. With this eandour does the gentleman speak of himself and others. The same frankness runs through all his conversation. The military part of his life has furnished him with many adventures, in the relation of which he is very agreeable to the company; for he is never overbearing, though accustomed to command men in the utmost degree below him; nor ever too obsequious, from a habit of obeying men highly above him. Advancement in the army is often given to the person who______.
4 Next to Sir Andrew in the club-room sits Captain Sentry, a gentleman of great cour age, good understanding, but invincible modesty. He is one of those that deserve very well, but are very awkward at putting their talents within the observation of such as should take notice of them. He was some years a captain, and behaved himself with great gallantry in several engagements and at several sieges; but having a small estate of his own, and being next heir to Sir Roger, he has quitted a way of life in which no man can rise suitably to his merit, who is not something of a courtier as well as a soldier. I have heard him often lament that in a profession where merit is placed in so conspicuous a view, impudence should get the better of modesty. When he had talked to this purpose; I never heard him make a sour expression, but frankly confess that he left the world because he was not fit for it. A strict honesty, and an even regular behavior, are in themselves obsta cles to him that must press through crowds, who endeavour at the same end with himself, the favor of a commander. He will, however, in his way of talk excuse generals for not disposing according to men’s desert, or inquiring into it; for, says he, that the great man who has a mind to help me, has as many, to break through to come at me, as I have to come at him: therefore he will conclude that the man who would make a figure, especially in a military way, must get over all false modesty, and assist his patron against the impor tunity of other pretenders, by a proper assurance in his own vindication. He says it is a civil cowardice to be backward in asserting what you ought to expect, as it is a military fear to be slow in attacking when it is your duty. With this eandour does the gentleman speak of himself and others. The same frankness runs through all his conversation. The military part of his life has furnished him with many adventures, in the relation of which he is very agreeable to the company; for he is never overbearing, though accustomed to command men in the utmost degree below him; nor ever too obsequious, from a habit of obeying men highly above him. "Candour" means______.
微信支付 
支付宝支付