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
When animals make long journeys across places where there is no food or shelter, such as deserts or oceans, it is very important
When animals make long journeys across places where there is no food or shelter, such as deserts or oceans, it is very important
admin
2013-03-25
69
问题
When animals make long journeys across places where there is no food or shelter, such as deserts or oceans, it is very important that they should be able to find their way accurately.
Birds find their way by the stars at night and by the sun during the day. People thought that this was impossible. Then some scientists made an experiment. They put some migrating birds(候鸟)in cages inside a planetarium(天象图). When the operator turned the artificial sky(人造天空)round, the birds began to fly to the sides of the cage. Every time he moved it, the birds moved to a new position. Scientists discovered that they always flew toward the direction in which they would have flown if the sky had been real. This proved that they could see the stars and respond to them.
Many animals, especially birds, have a very precise sense of time, which is called their “internal clock”. In cloudy weather, birds delay setting off on long journeys, but if the cloud lasts for a long time, they must go at last, to complete their migration in time. In such conditions, they are able to steer(引导)by following the magnetic field(磁场)of the earth. We could say that they have their own special compass inside them, which tells the right direction to go.
Most migrating animals travel in groups, sometimes in very large numbers. This makes it more likely that they will find the right way, especially when the group has experienced animals which have made the journey before.
What is the passage mainly about?
选项
A、How animals sense the time.
B、How animals find their way in migration.
C、Why animals like to travel in groups.
D、How scientists find the secret of birds.
答案
B
解析
总结归纳题。通读全文, 我们可以得知整篇文章都在讲动物是怎么迁移的, 故选B。
转载请注明原文地址:https://kaotiyun.com/show/sBeK777K
本试题收录于:
大学英语三级A级题库大学英语三级分类
0
大学英语三级A级
大学英语三级
相关试题推荐
Wewouldliketotakethisopportunitytoexpressoursincere______(appreciate)ofyourhelp.
Bytheendofthisyear,Mr.Brown______(be)herefortwentyyears.
A、Richardisthebeststudentinherclass.B、Richardisgoodineveryway.C、Richardisnotagoodstudentatall.D、Richardca
SALESCONTRACTContractNo.CP1023Date:12July,2005Signedat:ShanghaiSe
Britishuniversityentrants(新学员)expecttobeprovidedwithwashingmachinesanddryersintheirrooms,andevencarparkingspa
Inthisletter,ABCCompanyispromoting______.Theword"boost"(Line5,Para.3)probablymeans______.
Mostofthepeople(invite)______tothedinnerpartyyesterdayweremyfriends.
A、Inapassportoffice.B、Atanairport.C、Inapolicestation.D、Outsideaticketoffice.B
______thepunishmentwasunfair,heaccepteditwithoutcomplaint.
随机试题
已知工质的压力和温度,在该温度下,当压力小于饱和压力时,工质所处的状态是()。
调节肾小管Na+-K+交换的激素是______;调节肾小管对水重吸收的激素是______。
A.五味消毒饮B.仙方活命饮C.黄连解毒汤D.犀角地黄汤E.清骨散疮疡内治,清气分热之常用方剂是
某直辖市政府以“摩的”遍地开花影响市容为由发布一项通知,要求凡是从事“摩的”运营的都应当取得市政府的运营许可证。关于此运营许可证,下列说法哪一项是正确的?()
根据土的抗剪强度指标确定地基承载力可按下式计算:fv=Mbγb+Mdγ0d+McCk以下关于上式的适用条件e≤0.033b的解释______项正确。
对于已确认减值损失的可供出售债务工具,在随后的会计期间公允价值已上升且客观上与原减值损失确认后发生的事项有关的,原确认的减值损失应当予以转回,计入()科目。
社区服务站接受街道办事处和社区党组织的(),接受政府职能部门的(),同时接受社区居民委员会的()。
(1)夏朝灭亡(2)商鞅变法(3)统一六国(4)周公吐哺(5)卧薪尝胆
()是指一个人为了实现道德要求,战胜利己的动机作出合理的决定和排除内外障碍坚持道德行为的能力。
设X1,X2,…,Xm为来自二项分布总体B(n,p)的简单随机样本,和S2分别为样本均值和样本方差.若+kS2为np2的无偏估计量,则k=________.
最新回复
(
0
)