单选题
People, like most animals, are naturally lazy. So the ascent of mankind is something of a mystery. Humans who make their livings hunting and gathering in the traditional way do not have to put much effort into it. Farmers who rely on rain to water their crops work significantly harder, and lead unhealthier lives. But the real back-breaking is that carried out by farmers who use irrigation. Yet it was the invention of irrigation, at first sight so harmful to its practitioners that actually produced a sufficient surplus to feed the priests, scholars, artists and so on whose activities are collectively thought of as "civilization". In the past 10,000 years, the world's climate has become temporarily colder and drier on several occasions. The first of these, known as the Younger Dryas, after a tundra-loving plant that thrived during it, occurred at the same time as the beginning of agriculture in northern Mesopotamia. It is widely believed that this was not a coincidence. The drying and cooling of the Younger Dryas adversely affected the food supply of hunter-gatherers. That would have created an incentive for agriculture to spread once some bright spark invented it. Why farmers then moved on to irrigation is, however, far from clear. But Harvey Weiss, of Yale University, thinks he knows. Dr. Weiss observes that the development of irrigation coincides with a second cool, dry period, some 8,200 years ago. His analysis of rainfall patterns in the area suggests that rainfall in agriculture's upper-Mesopotamian heartland would, at this time, have fallen below the level needed to sustain farming reliably. Farmers would thus have been forced out of the area in search of other opportunities. Once again, an innovative spark was required. But it clearly occurred to some of these displaced farmers that the slow-moving waters of the lower Tigris and Euphrates, near sea level, could be diverted using canals and used to water crops. And the rest, as the cliche has it, is history. So climate change helped to intensify agriculture, and thus start civilization. But an equally intriguing idea is that the spread of agriculture caused climate change. In this case, the presumed criminal is forest clearance. Most of the land cultivated by early farmers in the Middle East would have been forested. When the trees that grew there were cleared, the carbon they contained ended up in the atmosphere as carbon dioxide. Moreover, one form of farming—the cultivation of rice in waterlogged fields—generates methane, in large quantities. William Ruddiman, of the University of Virginia, explained that, in combination, these two phenomena had warmed the atmosphere prior to the start of the industrial era. As environmentalists are wont to observe, mankind is part of nature. These studies show just how intimate the relationship is.
单选题
The invention of irrigation is meaningful because it could help to
【正确答案】
B
【答案解析】本题问灌溉发明具有重要意义之原因何在。首段中“Yet it was the invention of irrigation，…that actually produced a sufficient surplus to feed the priests，scholars，artists…”指出灌溉的发明使得人们有足够的食物来哺育文明的发展。这说明灌溉使农业增产。故[B]“提高了农业产量”正确。 [A]减轻了农民的劳动强度：首段中“But the real back-breaking is that carried out by farmers who use irrigation．”和“Yet it was the invention of irrigation，at first sight so harmful to its practitioners…”都表明事实上灌溉是加重了农民的劳累。 [C]使耕种变得容易多了：灌溉使农民更劳累，说明灌溉使耕种变复杂了，而不是简单。 [D]消除了人的懒惰性：首段首句提到“People，like most animals，are naturally lazy．”表明人天生有惰性。灌溉发明后，农民更辛苦了，从另一方面来说，他们是比以前更勤快了。但从后文可知进行灌溉也是迫于生计。人天生的惰性并没有因此而消除。
单选题
According to Dr. Weiss, the second cool and dry period eventually
【正确答案】
B
【答案解析】本题问根据Dr．Weiss所说，第二干冷期所产生的影响是什么。第三段中“…Dr．Weiss observes that the development of irrigation coincides with a second cool，dry period…Farmers would thus have been forced out of the area in search of other opportunities．”Dr．Weiss认为干冷期将会迫使农民背井离乡寻求别的生计。第四段中紧接上段“Once again，an innovative spark was required…some of these displaced farmers that the slow-moving waters…could be diverted using canals…”表明农民在走投无路的时候想到了使用沟渠引水灌溉的办法，于是发明了灌溉。所以[B]“促进了沟渠的利用”正确。 [A]改变了生长季节：第三段中“His analysis…suggests that rainfall…would…have fallen below the level needed to sustain farming reliably．”表明干冷期的降水量无法保证耕种正常进行。但这并不表明生长季节发生了变化。 [C]迫使农民放弃了农业：文中提到“Farmers would thus have been forced out of the area in search of other opportunities．”。接着又提到农民在走投无路的时候想到了利用沟渠引水灌溉的办法。也就是说，由于发明了灌溉，农民们并没有放弃农业。 [D]导致人口减少：第三段中“Farmers would thus have been forced out of the area”及第四段中“some of these displaced fanners”都表明农民是被迫迁移，而没有谈到人口数量减少。当然，由于气候对农业的影响，人口很可能减少，但是在本文中没有谈到这点，因此不能选本项。本项只是出题者根据常识而设置的干扰项。
单选题
From the first four paragraphs, we can infer that the dawn of civilization
【正确答案】
A
【答案解析】本题问从前四段可以推出文明的起源怎么样。首段末句提到灌溉的发明表面看起来使农民更加辛苦，但是却促进了文明的发展。随后三段则详细讨论气候的变化使农业变得辛苦，但同时也促进了文明的发展。由此可以看出，文明与人类的艰辛相辅相成的。故A项“伴随着人类生存的艰辛”正确。 [B]是人类还不知道的秘密：第三段首句提到“far from clear”，但文中指的是农民如何学会灌溉还不是非常清楚(但文中也提出了一种观点)，而不是对文明的起源不清楚。首段末句已经明确说明灌溉使农业产量增加，从而促进了文明的发展。 [C]可归因于祖先们的创造火花：过于片面。文明的起源虽然离不开某些人的智慧火花，但它不是决定因素。气候的变化迫使人们必须寻求更好的耕种方式，从而逐渐发明了灌溉的方式，这才是决定性的。 [D]被结束于那时的历史书所记载：第四段末句提到“the rest，as the cliche has it，is history”，意思是说以后的历史人人都知道了，这里并没有历史书的含义，更谈不上“ending at that time”了。
【答案解析】本题问文章的主旨是什么。文章首段提到农业中灌溉的发明“produced a sufficient surplus to feed the priests， scholars，artists and so on whose activities are collectively thought of as ‘civilization’．”接下来指出哺育文明的灌溉是由气候变化导致的；最后一段首句“So climate change helped to intensify agriculture，and thus start civilization．”揭示了全文主题——气候变化导致文明产生。故[A]“气候变化与文明的关系”正确。 [B]全球气候变化的历史：文章在第二、三段确实谈到了历史上曾经发生过的气候变化，但并非中心话题。 [C]自然界和人类社会的互动：本文主要谈论气候变化，“自然界”范围过宽。 [D]农业发展的影响：文中是提到了农业发展产生的一些影响，如末段中的毁林开荒等。但这只是本文的一项具体内容。