首页
登录
职称英语
[originaltext] Thefiddler crab ( 招潮蟹) is a living clock. It indicates the ti
[originaltext] Thefiddler crab ( 招潮蟹) is a living clock. It indicates the ti
游客
2023-09-12
87
管理
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、The Rhythmic Cycle of the Sun and the Tide
B、Discoveries in Biology
C、A Scientific Study
D、A Living Clock
答案
D
解析
概括归纳题 文章的关键词是fiddler crab,文章主要讲述了其肤色的规律性变化。
转载请注明原文地址:http://tihaiku.com/zcyy/3008745.html
相关试题推荐
【B1】______[br]【B10】______[originaltext]Thedog,calledPrince,wasan(
【B1】______[br]【B7】______[originaltext]Thedog,calledPrince,wasan(2
【B1】______[br]【B5】______[originaltext]Thedog,calledPrince,wasan(2
【B1】______[br]【B4】______[originaltext]Thedog,calledPrince,wasan(2
【B1】______[br]【B2】______[originaltext]Thedog,calledPrince,wasan(2
[originaltext]OnecrossingoftheAtlanticisverymuchlikeanother;andpe
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyo
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyo
[originaltext]Livingthingstakefromtheirenvironmentandgivebacktothe
[originaltext]Livingthingstakefromtheirenvironmentandgivebacktothe
随机试题
I’vebeendrivingbigtrucksfor37yearsandIwishedtostayontheroadun
______bythebeautyofnature,thegirlfromLondondecidedtospendanothertw
TIRADE:A、sermonB、deviationC、disputeD、reasonableappealE、composeddiscourse
ThecultureoftheUnitedStatesisaWesterncultureoriginallyinfluence
ContextDefinition:Ourenvironment,particularlyitssignificanceduring【D1】___
希望工程(ProjectHope)是于1989年发起的一项公益事业,以救助贫困地区失学儿童(youngdropouts)为目的。帮助建设希望小学与资助
普通合伙企业是指依法在中国境内设立的由各合伙人订立合伙协议,共同出资、合伙经营
矿山电力负荷分为( )级。A.2 B.3 C.4 D.5
漏电保护又称剩余电流保护,在保障用电安全方面起着重要作用。运行中的漏电保护装置必
流量取源部件在水平和倾斜的管道上安装时,当测量蒸汽时,取压口方位应在()。A.管
最新回复
(
0
)