托福阅读自然科学话题文章：Desert Animals

 　　自然学科是托福阅读文章题材中比较常见的类型，本系列为大家汇总整理了多篇托福阅读自然科学类文章，大家在托福备考时可以有针对性的进行复习，小编为大家带来的是托福阅读自然科学话题Desert Animals，并附有相应的练习，希望大家都能顺利拿下托福阅读高分。

　　Desert Animals

　　Keywords:desert mammals, body temperature, an excessive buildup of heat, camel, Desert-adapted mammals

　　Large animals that inhabit 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 also depart from the normale mammalian practice of maintaining a constant body temperature. Instead of trying to keep down the body temperature deep inside the body, which would involve the expenditure¹ of water and energy, desert mammals allow their temperatures to rise to what would normally be fever height, and temperatures as high as 46 degrees Celsius² have been measured in Grant's gazelles. 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 large desert animals is to tolerate the loss of body water to a point that would be fatal for nonadapted 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 replenish³ this water loss at one drink. Desert animals can drink prodigious⁴ volumes in a short time, and camels have been known to imbibe⁵ over 100 liters in a few minutes. A very dehydrated person, on the other hand, cannot drink enough water to dehydrate⁶ at one session, because the human stomach is not sufficiently⁷ big and because a too rapid dilution⁸ of the body fluids causes death from water intoxication⁹. The tolerance¹⁰ 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 sparse¹¹ 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 ?

　　(A) Weather variations in the desert

　　(B) Adaptations of desert animals

　　(C) Diseases of desert animals

　　(D) Human use of desert animals

　　2. According to the passage, why is light coloring an advantage to large desert animals?

　　(A) It helps them hide from predators¹².

　　(B) It does not absorb sunlight as much as dark colors.

　　(C) It helps them see their young at night.

　　(D) It keeps them cool at night.

　　3. The word "maintaining" in line 4 is closest in meaning to

　　(A) measuring

　　(B) inheriting

　　(C) preserving

　　(D) delaying

　　4. The author uses Grant's gazelle as an example of

　　(A) an animal with a low average temperature

　　(B) an animal that is not as well adapted as the camel

　　(C) a desert animal that can withstand high body temperatures

　　(D) a desert animal with a constant body temperature

　　5. When is the internal temperature of a large desert mammal lowest?

　　(A) Just before sunrise

　　(B) In the middle of the day

　　(C) Just after sunset

　　(D) Just after drinking

　　6. The word "tolerate" in line 13 is closest in meaning to

　　(A) endure

　　(B) replace

　　(C) compensate¹³

　　(D) reduce

　　7. What causes water intoxication?

　　(A) Drinking too much water very quickly

　　(B) Drinking polluted water

　　(C) Bacteria in water

　　(D) Lack of water

　　8. What does the author imply about desert-adapted mammals?

　　(A) They do not need to eat much food.

　　(B) The can eat large quantities quickly.

　　(C) They easily lose their appetites.

　　(D) They can travel long distances looking for food.

　　9. Why does the author mention humans in the second paragraph?

　　(A) To show how they use camels

　　(B) To contrast them to desert mammals

　　(C) To give instructions about desert survival

　　(D) To show how they have adapted to desert life

　　10. The word "obtain" in line 23 is closest in meaning to

　　(A) digest

　　(B) carry

　　(C) save

　　(D) get

　　11. Which of the following is NOT mentioned as an adaptation of large desert animals?

　　(A) Variation in body temperatures

　　(B) Eating while dehydrated

　　(C) Drinking water quickly

　　(D) Being active at night

　　参考答案：BBCCB AABBD D

　　以上就是为大家整理的托福阅读自然科学类文章之Desert Animals，作为自然科学分类下动物类的话题，这是托福阅读备考中的一大重点，希望能够帮助大家备考。预祝大家托福考试取得好成绩!

1 expenditure   

n.(时间、劳力、金钱等)支出；使用，消耗

参考例句：

• The entry of all expenditure is necessary.有必要把一切开支入账。
• The monthly expenditure of our family is four hundred dollars altogether.我们一家的开销每月共计四百元。

2 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

3 replenish   

vt.补充；(把…)装满；(再)填满

参考例句：

• I always replenish my food supply before it is depleted.我总是在我的食物吃完之前加以补充。
• We have to import an extra 4 million tons of wheat to replenish our reserves.我们不得不额外进口四百万吨小麦以补充我们的储备。

4 prodigious   

adj.惊人的，奇妙的；异常的；巨大的；庞大的

参考例句：

• This business generates cash in prodigious amounts.这种业务收益丰厚。
• He impressed all who met him with his prodigious memory.他惊人的记忆力让所有见过他的人都印象深刻。

5 imbibe   

v.喝，饮；吸入，吸收

参考例句：

• Plants imbibe nourishment usually through their leaves and roots.植物通常经过叶和根吸收养分。
• I always imbibe fresh air in the woods.我经常在树林里呼吸新鲜空气。

6 dehydrate   

vt.使脱水

参考例句：

• People can very quickly dehydrate in the desert.人在沙漠里很快就会脱水。
• Without these structures, many warm-blooded animals would quickly dehydrate,especially in dry climates.没有这样的结构，许多温血动物将很快脱水，特别是在干燥的气候条件下。

7 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

8 dilution   

n.稀释，淡化

参考例句：

• There is no hard and fast rule about dilution.至于稀释程度，没有严格的规定。
• He attributed this to a dilution effect of the herbicide.他把这归因于除草剂的稀释效应。

9 intoxication   

n.wild excitement;drunkenness；poisoning

参考例句：

• He began to drink, drank himself to intoxication, till he slept obliterated. 他一直喝，喝到他快要迷糊地睡着了。
• Predator: Intoxication-Damage over time effect will now stack with other allies. Predator:Intoxication,持续性伤害的效果将会与队友相加。

10 tolerance   

n.宽容；容忍，忍受；耐药力；公差

参考例句：

• Tolerance is one of his strengths.宽容是他的一个优点。
• Human beings have limited tolerance of noise.人类对噪音的忍耐力有限。

11 sparse   

adj.稀疏的，稀稀落落的，薄的

参考例句：

• The teacher's house is in the suburb where the houses are sparse.老师的家在郊区，那里稀稀拉拉有几处房子。
• The sparse vegetation will only feed a small population of animals.稀疏的植物只够喂养少量的动物。

12 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

13 compensate   

vt.补偿，赔偿；酬报 vi.弥补；补偿；抵消

参考例句：

• She used her good looks to compensate her lack of intelligence. 她利用她漂亮的外表来弥补智力的不足。
• Nothing can compensate for the loss of one's health. 一个人失去了键康是不可弥补的。