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
专升本
The fiddler crab is a living clock. It indicates the time of day by the color of its skin, which is dark by day and pale by nigh
The fiddler crab is a living clock. It indicates the time of day by the color of its skin, which is dark by day and pale by nigh
admin
2015-10-30
35
问题
The fiddler crab 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 twenty-four-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 crab’ s 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 fifty 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 was caught!
The crab’ s changing color______.
选项
A、tells the crab what time it is
B、protects the crab from the sunlight
C、keeps the crab warm
D、is of no real use
答案
B
解析
文章第三段第一句This characteristicprobably evolved in response to the rhythm of thesun,to help protect the crab from sunlight andenemies.所以B正确。
转载请注明原文地址:https://kaotiyun.com/show/XfYC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
AustraliaisnearlyaslargeastheUnitedStates,butmostofitistoodryforpeopletolivein.Aroundthisdrypartarelar
Inordertolearnaforeignlanguagewell,itisnecessarytoovercomethefearofmakingmistakes.Iftheprimarygoal(目标)of
Hesaidhehadnodifficulty______theboathimself.
Lastyear,myclassmateJaneandIgraduatedfromanordinarynormaluniversity.Likemostofthestudentswhohadjuststepped
AirportbaggagescreenersintheUSA,displayingseizedchainsaws,machetesandknives,【21】travelerstochecktheirluggagefor
Whenscientistsaretryingtounderstandaparticularsetofphenomena,theyoftenmakeuseofa"model."Amodel,inthescient
Readthefollowingdialogueandtrytofillupthegapswithproperwords,phrases,orsentences.Customer:DoyouChargefo
Notallpeoplegottheirnames【21】theirfathers.Somegottheirnamesfromtheplacesthey【22】.Forexample,afamilyhadlived
Forsometimepastithasbeenwidelyacceptedthatbabiesandothercreatureslearntodethingsbecausecertainactsleadto"
Lookingbackonmychildhood,Iamconvincedthatnaturalistsarebornandnotmade.Althoughwewerebroughtupinthesameway
随机试题
知识产权
如果货物在空运单上约定的到达时间届满后()天内仍没到达,收货人便可以向承运人主张权利。
纳税人将自产、委托加工或者外购的货物用于集体福利或个人消费的,均视同销售,征收增值税。()
企业发生的财务费用,在编制现金流量表时,均应作为筹资活动项目反映。()
实施“中小学教师继续教育工程”应放在突出地位的有()。
叶圣陶、郑振铎等都是江浙人,有着江浙知识分子特有的理性和宽容。他们像朱自清一样,都是新文学的热心鼓吹者,写得一手漂亮的白话散文。他们接受过五四新文化的洗礼,______,无论对中西之学,都采取平和的一视同仁态度。填入横线上最恰当的是()。
债务人甲怠于行使其对乙的到期债权,对债权人丙造成损害的,债权人丙可以向人民法院请求以自己的名义代为行使债务人的债权。但债权人丙提起代位权诉讼,应当符合的条件不包括()。
中国共产党在马克思主义指导下,立足中国国情,走出以农村包围城市、武装夺取政权的新民主主义道路。这给我们的哲学启示是()。
下列关于隋唐时期货币表述准确的是()。①隋朝使用五铢钱②开元年间开始统一使用开元通宝③开元通宝是唐朝的通用货币④开元通宝是唐代以后历代王朝货币的范式
共同要素说强调以下哪种因素在学习中的作用?
最新回复
(
0
)