首页
登录
职称英语
Large animals that live in the desert have evolved a number of adaptations f
Large animals that live in the desert have evolved a number of adaptations f
游客
2024-02-24
8
管理
问题
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 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 expenditure 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 Celsius have been measured in Grant’s gazelles (一种小羚羊). 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 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 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 non-adapted animals. The camel can lose up to 30 percent of its body weight as water with no 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 supply this water loss at one drink. Desert animals can drink great volumes in a short time, and camels have been known to take in over 100 liters in a few minutes. A very dehydrated (脱水) person, on the other hand, can not drink enough water to supply water at one session, because the human stomach is not sufficient big and because a too rapid dilution (稀释) of the body fluid causes death from water intoxication. The tolerance of water loss is of obvious advantage in the desert, as animals don’ t have to remain near a water hole but can obtain food from grazing sparse and far-flung natures. 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. [br] Why is light coloring an advantage to large desert animals?
选项
A、It helps protect them from other dangerous animals.
B、It keeps them cool during the day.
C、It keeps them warm by reflecting light.
D、It helps them maintain a constant body temperature.
答案
B
解析
本题测试文章细节。见本文第一段第二句,"light color"反射而不是吸收阳光,它有助于沙漠动物白天降低体温。因此[B]是正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3478622.html
相关试题推荐
TheEuropeanUnionhadapprovedanumberofgeneticallymodifiedcropsuntil
TheEuropeanUnionhadapprovedanumberofgeneticallymodifiedcropsuntil
TheEuropeanUnionhadapprovedanumberofgeneticallymodifiedcropsuntil
TheEuropeanUnionhadapprovedanumberofgeneticallymodifiedcropsuntil
TheEuropeanUnionhadapprovedanumberofgeneticallymodifiedcropsuntil
TheEuropeanUnionhadapprovedanumberofgeneticallymodifiedcropsuntil
[originaltext]Manyanimalsareusedtohelpscientistsfindoutwhatwillh
[originaltext]Manyanimalsareusedtohelpscientistsfindoutwhatwillh
[audioFiles]audio_eufm_104(20106)[/audioFiles]A、Fish.B、Fruits.C、Smallanimals
Thepartnershipbetweenhumansandanimalsdatesbacktothefirstdomestica
随机试题
Learningtoplayamusicalinstrumentcanchangeyourbrain,withaUSrevie
UniversalHealthCare,Worldwide,IsWithinReachA)Bymanym
[img]2021m3x/ct_ve01004003m_eyyjsccloze_0048_202103[/img]Whenweseeab
MostChineseliketodrinktea.Butsome
人民广播史上第一位播音员是( )。A.姚雯 B.徐瑞璋 C.钱家楣 D.
共用题干 甲房地产开发公司(以下简称甲公司)拟开发一写字楼项目,该项目的优势初
下列化合物中具有抗肿瘤作用的是A.薄荷醇 B.银杏内酯 C.青蒿素 D.紫
战国后期,我国出现的具有世界影响的教育文献是( )。A.《大学》 B.《中庸
会员制期货交易所应当对会员大会所表决事项制作会议纪要.由出席会议的全体会员签名。
冷弯性能是指钢材在常温下承受弯曲变形的能力,钢材的冷弯性能指标是通过()进行区
最新回复
(
0
)