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
A、They change color every 50 minutes. B、They change color more quickly. C、They change color more slowly. D、They change color on
A、They change color every 50 minutes. B、They change color more quickly. C、They change color more slowly. D、They change color on
admin
2010-05-09
39
问题
Thefiddler crab ( 招潮蟹) is a living clock. It indicates the time of day by the color of its skin, which is dark by day and pale by night. The crab’s changing skin color follows a regular 24-hour cycle that exactly matches the daily rhythm of the sun.
Does the crab actually keep time, or does its skin simply respond to the sun’s rays, changing color according to the amount of light that strikes it? To find out, biologists kept crabs in a dark room for two months. Even without daylight, the crabs’skin color continued to change precisely on schedule.
This characteristic probably evolved in response to the rhythm of the sun, to help protect the crab from sunlight and enemies. After millions of years it has become completely regulated inside the living body of the crab.
The biologists noticed that once each day the color of the fiddler crab is especially dark, and that each day this occurs 50 minutes later than on the day before. From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides. The crab’s period of greatest darkening is precisely the time of low tide on the beach where it is caught.
选项
A、They change color every 50 minutes.
B、They change color more quickly.
C、They change color more slowly.
D、They change color on the same schedule.
答案
D
解析
事实细节题 生物学家的实验表明:招潮蟹不受光的影响,在黑暗的环境里仍然很有规律地变换肤色。
转载请注明原文地址:https://kaotiyun.com/show/JZOK777K
0
大学英语六级
相关试题推荐
A、Losthisbankbook.B、Missedherhomeway.C、Failedtoborrowbooks.D、Puzzledbyregulations.CWhatisthematterwiththewo
Thepassagemainlydealswithhowforeignteachersshouldtrytogetmorepaidwhentheyintendtoworkforaschool.Whythef
A、Theymadethembyknives.B、Theyfoundadequatestones.C、Theyusedbonesofanimals.D、Theymadetoolsbyhittingstoneagain
Insomeplacesleaveswillfalloffthetreesbeforetheychangecolorsintheautumn.Upuntilnow,scientistsstillcouldnot
Whattopicisthepassagemainlyconcernedwith?Theotherhigheranimalsfailtouselanguageasmandoesbecause______.
GriffithworkedforafirmthatspecializedineconomicdevelopmentinWashingtonD.C.becausesheneededmoneytopayforherd
TheNationalTrustis______.LordLothiansaidmostoftheancienthouseswere______.
Accordingtothepassage,colorblindnesscanbedangerousincertainoccupationslike______.Whenmillionsofrodsinoureye
BluetoothWhenyouusecomputers,entertainmentsystemsortelephones,thevariouspiecesandpartsofthesystemsmakeupa
A、InIowa.B、InNewYork.C、InFrankfurt.D、Notmentioned.A
随机试题
雷格斯的行政生态理论认为工业社会行政模式的最主要特点是行政系统在结构和功能上实现了()
A、松动、脱落B、变色C、穿孔、破裂D、磨损E、折断牙合力大,同定桥连接体薄弱可导致
男,61岁。患有高血压,同时伴有2型糖尿病,尿蛋白(+)。选择最佳降压药物为()
患者,男性,32岁。患急性扁桃体炎。医嘱青霉素过敏试验阴性后,肌内注射160万U青霉素。护士在青霉素过敏试验前才配置试验液的目的是
可行性研究的进程的顺序是()。
测量的基本要求是()。
将考评量表分为三个等级,即极好、满意和不满意,使被考评者容易分清什么是“正确的”,什么是“错误的”,这种绩效考核方法是()。
设A,B是两个随机事件,且0<P(A)<1,P(B)>0,P(B|A)=P(B|A),则必有
交换机只接收帧的14个字节便立刻转发数据帧的交换模式是()。
ThePopularityofEnglishI.PresentstatusofEnglishAEnglishasanative/firstlanguageBEnglishasalinguafranca:alang
最新回复
(
0
)