Large animals that live in the desert have evolved a number of adaptations for reducing the effects of extreme heat. One adaptation is to be light in color, and to reflect rather than absorb the sun’s rays. Desert mammals (哺乳动物) also depart from the normal practice of maintaining a constant body temperature. Instead of trying to keep down the body temperature deep inside the body, which would involve the consumption of water and energy, desert mammals allow their temperature to rise to what would normally be fever height. The overheated body then cools down during the cold desert night, and indeed the temperature may fall unusually low by dawn, as low as 34 degrees Celsius in the camel. This is an advantage since the heat of the first few hours of daylight is absorbed in warming up the body, and an excessive buildup of heat does not begin until well into the day.
Another strategy of the large desert animals is to tolerate the loss of body water to a point that would be fatal for non-adapted animals. The camel can lose up to 30 percent of its body weight as water without harm to itself whereas human beings die after losing only 12 to 13 percent of their body weight. An equally important adaptation is the ability to replenish (补充) this water loss as one drink. Desert animals can drink enormous volumes in a short time, and camels have been known to drink over 100 liters in a few minutes. A very dehydrated (脱水的) person, on the other hand, cannot drink enough water to rehydrate at one session, because the human stomach is not sufficiently big and because a too rapid dilution (稀释) of the body fluids causes death from water poisoning. The tolerance of water loss is of obvious advantage in the desert, as animals do not have to remain near a water hole but can obtain food from grazing sparse and far-flung pastures. Desert-adapted mammals have the further ability to feed normally when extremely dehydrated, it is a common experience in people that appetite is lost even under conditions of moderate thirst.
1. What is the main topic of the passage?
2. When is the internal temperature of a large desert mammal the lowest?
3. What causes water poisoning?
4. What does the author imply about desert-adapted mammals?
5. Why does the author mention human in the second paragraph?
问题1选项
A.Weather valuations in the desert.
B.Adaptations of desert animals.
C.Diseases of desert animals.
D.Human use of desert animals.
问题2选项
A.Just before sunrise.
B.In the middle of the day.
C.Just after sunset.
D.Just after drinking.
问题3选项
A.Drinking too much water very quickly.
B.Drinking polluted water.
C.Bacteria in water.
D.Lack of water.
问题4选项
A.They do not need to eat much food.
B.They can drink large quantities of water quickly.
C.They easily lose their appetites.
D.They can survive without drinking any water for a long time.
问题5选项
A.To show how they use camels.
B.To contrast them with desert mammals.
C.To give instructions about desert survival.
D.To show how they have adapted to desert life.
第1题:B
第2题:A
第3题:A
第4题:B
第5题:B
第1题:
【选项释义】
What is the main topic of the passage? 这篇文章的主题是什么？
A. Weather valuations in the desert. A. 沙漠中的天气评估。
B. Adaptations of desert animals. B. 沙漠中的动物的适应性。
C. Diseases of desert animals. C. 沙漠中的动物的疾病。
D. Human use of desert animals. D. 人类对沙漠中的动物的利用。
【考查点】主旨大意题。
【解题思路】文章第一段讲到生活在沙漠中的大型动物进化出适应极端高温的能力（adaptations for reducing the effects of extreme heat），第二段以骆驼为例讲到沙漠中的大型动物在水分流失（the loss of body water）和补充（replenish this water loss），进食（feed）上的适应性，所以本文讲的是沙漠中动物的适应性。因此B选项正确。
【干扰项排除】
A选项“沙漠中的天气评估”，C选项“沙漠中动物的疾病”和D选项“人类对沙漠中动物的利用”：文中没有提到，属于无中生有。
第2题:
【选项释义】
When is the internal temperature of a large desert mammal the lowest? 大型沙漠中的哺乳动物的体内温度什么时候最低？
A. Just before sunrise. A. 太阳快升起的时候
B. In the middle of the day. B. 在中午。
C. Just after sunset. C. 太阳刚下山之后
D. Just after drinking. D. 刚喝水后
【考查点】推理判断题。
【解题思路】根据题干中信息词temperature和lowest定位到第一段倒数第二句，该处讲到“在沙漠的寒冷夜晚，过热的身体会冷却下来（cools down during the cold desert night），事实上，在黎明前温度可能会异常低（fall unusually low by dawn）。”，可知在沙漠中，大型哺乳动物的体温在夜晚下降，并且在黎明的时候最低。因此A选项正确。
【干扰项排除】
B选项“在中午”，C选项“太阳刚下山之后”和D选项“刚喝水后”：不符合原文内容，属于曲解原文。
第3题:
【选项释义】
What causes water poisoning? 水中毒的原因是什么？
A. Drinking too much water very quickly. A. 快速喝太多水。
B. Drinking polluted water. B. 饮用被污染的水。
C. Bacteria in water. C. 水中的细菌。
D. Lack of water. D. 缺水。
【考查点】事实细节题。
【解题思路】根据题干中信息词water poisoning定位到第二段第五句，该处讲到“一个极度脱水的人不能一次性喝足够的水来补充水分，因为人的胃不够大，而且体液被过快稀释会导致水中毒死亡（rapid dilution of the body fluids causes death from water poisoning）。”，可知一次性喝太多水，体液被过快稀释是水中毒的原因。因此A选项正确。
【干扰项排除】
B选项“饮用被污染的水”，C选项“水中的细菌”和D选项“缺水”：不符合原文内容，属于曲解原文。
第4题:
【选项释义】
What does the author imply about desert-adapted mammals? 关于适应沙漠的哺乳动物，作者暗示了什么？
A. They do not need to eat much food. A. 它们不需要吃很多食物。
B. They can drink large quantities of water quickly. B. 它们可以快速地喝大量的水。
C. They easily lose their appetites. C. 它们很容易失去胃口。
D. They can survive without drinking any water for a long time. D. 它们可以在不喝水的情况下存活很长时间。
【考查点】推理判断题。
【解题思路】此题定位到第二段第四句，该处讲到“沙漠中的动物能在短时间内喝下大量的水（drink enormous volumes in a short time）。”，可知它们可以快速地喝大量的水。因此B选项正确。
【干扰项排除】
A选项“它们不需要吃很多食物”：文中没有提到，属于无中生有；
C选项“它们很容易失去胃口”：对应文章最后一句“适应沙漠的哺乳动物在极度脱水的情况下更有能力正常进食（further ability to feed normally）。”，可知它们不容易失去胃口，属于反向干扰；
D选项“它们可以在不喝水的情况下存活很长时间”：对应第二段第一句“大型沙漠动物的另一个策略是容忍身体水分流失到一定程度（tolerate the loss of body water to a point）。”，这里指的是在水分流失到一定程度内，它们可以存货，而不是说不喝水也可以存活很长时间，属于偷换概念。
第5题:
【选项释义】
Why does the author mention human in the second paragraph? 为什么作者在第二段提到人类？
A. to show how they use camels. A. 展示他们如何利用骆驼。
B. to contrast them with desert mammals. B. 与沙漠哺乳动物相比。
C. to give instructions about desert survival. C. 给出关于沙漠生存的指示。
D. to show how they have adapted to desert life. D. 表明人类是如何适应沙漠生活的。
【考查点】推理判断题。
【解题思路】第二段提到人类是因为把人和沙漠中的大型哺乳动物进行对比，突出它们可以承受较多的水分流失、可以快速喝大量的水、以及在沙漠中食欲不会很受影响的特点。因此B选项正确。
【干扰项排除】
A选项“展示他们如何利用骆驼”，C选项“给出关于沙漠生存的指示”和D选项“表明人类是如何适应沙漠生活的”：本段主要讲的是骆驼在沙漠中生存的具体情况，而不是人类，属于曲解原文。
