首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Large animals that live in the desert have evolved a number of adaptations for reducing the effects of extreme heat. One adaptat
Large animals that live in the desert have evolved a number of adaptations for reducing the effects of extreme heat. One adaptat
admin
2010-09-10
24
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.
The internal temperature of a large desert mammal is lowest______.
选项
A、just before sunrise
B、just after sunset
C、just after drinking
D、in the middle of the day
答案
A
解析
本题测试文章细节。见第一段中间"the temperature may fall unusually low by dawn,"意为“黎明时体温最低”,与[A]项选择(just before sunrise)同义。
转载请注明原文地址:https://jikaoti.com/ti/LFtFFFFM
0
大学英语四级
相关试题推荐
A、Shelearneditfromherfriends.B、ShetookFrenchlessonsatschool.C、Shelearneditfromherfather.D、ShetookFrenchless
TheriseofEnglishisaremarkablesuccessstory.WhenJuliusCaesarlandedinBritainnearlytwothousandyearsago,Englishd
A、Dr.WilliamsisverybusyonTuesday.B、Dr.Williamsusuallyseespatientspromptly.C、Dr.Williamsforgothisappointmentwit
A、Helikestheirspeciallanguageandmusic.B、Heknowstheyareaspecialgeneration.C、Hereallycan’tappreciatetheirstyles
EnglishLanguageDevelopmentOldEnglish,until1066ImmigrantsfromDenmarkandNWGermanyarrivedinBritaininthe5t
Forthispart,youareallowed30minutestowriteTheJobILikeBest.Youshouldwriteatleast120wordsfollowingtheoutlin
A、Henryusuallyworksdiligently.B、Henryhasbecomeamuchbetterstudent.C、Henryhaschangedherstudyhabitslately.D、Henry
A、Therearenospecialrelationshipsinthegroup.B、Agroupdatemaybeplannedinadvance.C、Oneispairedwithanotheronag
A、Sciencefictionisnotafairlynewinliterature.B、Sciencefictionisverypopularwithpeopletoday.’C、Sciencefictiononl
Thepartoftheenvironmentalmovementthatdrawsmyfirm’sattentionisthedesignofcities,buildingsandproducts.Whenwe
随机试题
羊水过多时,下列哪项正确
患者,男性,46岁,肥胖,有糖尿病和冠心病史10年,近来发现血压升高波动在(160~170)/(90~100)mmHg,伴有头痛头胀,检查血脂正常,肝肾无异常发现,有眼底动脉硬化。该患者的高血压危险分层属于
关于规则结构,下列说法不正确的是()
具有气孔或杏仁构造的岩石包括()
关于矿业工程施工现场管理工作的说法,正确的是()。
北京市海淀区的邓某与朝阳区的李某以及丰台区的A有限责任公司(以下简称A公司),在北京市昌平区共同设立了B有限责任公司(以下简称B公司)。后因邓某无力清偿个人借款20万元,债权人申请人民法院强制执行邓某在B公司的股权;法院强制执行时,北京市西城区的王某取得邓
学习迁移的种类依据不同的标准可划分为()。
一艘游艇在行驶中,突然发生海难,游艇上有八名游客等待救援,但是直升机每次只能够救援一个人。而此时天气非常寒冷,海水特别刺骨,游艇已坏,不停地漏水,随时有沉没的可能。请你将这八名游客按照营救的先后顺序进行排序。游客情况如下:1.将军,男,69岁,身
中国选举制度所具有的功能有()。
阅读以下配置信息,将(1)~(3)空缺处的命令填写完整。SW1>enable(进入特权模式)SWi#vlandatabase(设置VLAN配置子模式)SW1(vlan)#vtpserver(设置本交换机为
最新回复
(
0
)