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
71
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、To tell the crab what time it is.
B、To protect the crab from the sunlight and enemies.
C、To keep the crab warm.
D、To be of no real use.
答案
B
解析
事实细节题 文中谈到招潮蟹的肤色随时间变化是为了保护自己避开阳光和敌人的伤害。
转载请注明原文地址:https://tihaiku.com/zcyy/3008743.html
相关试题推荐
[originaltext]M:Iwouldliketosendane-mailtoafriendofmine.Couldyou
[originaltext]M:Iwouldliketosendane-mailtoafriendofmine.Couldyou
[originaltext]HowdoAmericanhusbandsfeelabouthavingworkingwives?Many
[originaltext]HowdoAmericanhusbandsfeelabouthavingworkingwives?Many
[originaltext]HowdoAmericanhusbandsfeelabouthavingworkingwives?Many
[originaltext]W:ProfessorMarnes,Iwonderifyoucanfillmeinonyourlectu
[originaltext]W:ProfessorMarnes,Iwonderifyoucanfillmeinonyourlectu
[originaltext]W:ProfessorMarnes,Iwonderifyoucanfillmeinonyourlectu
[originaltext]WhenlittleMidoriwastwoyearsold,sheoftenClimbedontot
[originaltext]WhenlittleMidoriwastwoyearsold,sheoftenClimbedontot
随机试题
[originaltext]Doyouknowhowmuchitcosts?[/originaltext]A、It’sFriday.B、It
[originaltext]M:Icancometoyourhouseinhalfanhour.W:Soyouwillbehe
[originaltext]Aftershoppingformostoftheday,acouplereturntofindt
资料 2013年5月,某审计组按照《党政主要领导干部和国有企业领导人员经济责
材料的运杂费是指材料自()的费用。A.交货地点至工地现场 B.供应地点
下列哪种方法可增大超声波在粗晶材料中的穿透能力?()A.用直径较小的探头进行检验
取得招标文件以后,首要的工作是( )。A.调查投标工程的自然、经济和社会条件
(2021年上半年真题)班上有人遗失了财物,孔老师未经调查就怀疑是学生熊某偷拿了
光电缆敷设时,施工过程中光缆的弯曲半径不应小于光缆外径的( )。A.8倍 B.
男婴,4个月,人工喂养,未添加辅食,2天来清咳、流涕,伴低热,今晨抽搐4次,每次
最新回复
(
0
)