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
Why don’t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for many ye
Why don’t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for many ye
admin
2014-04-23
32
问题
Why don’t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for many years. Now they’re beginning to fill in the blanks.
Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly by night? Tests with artificial stars have proved that certain night-flying birds are able to follow the stars in their long-distance flights.
A dove (鸽子) had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The bird’s cage was placed under an artificial star-filled sky. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the artificial stars caused a change in the direction of his flight.
But the stars are apparently their principal means of navigation (航行) only. When the stars are hidden by clouds, they seemingly find their way by such landmarks as mountain ranges, coast lines, and river courses. But when it’s too dark to see these, the doves circle helplessly, unable to find their way.
The experiment with the dove indicated that______.
选项
A、birds have to be taught to navigate
B、a bird that has been caged will not fly long distances
C、some birds cannot fly at night
D、some birds seem to follow the stars when they fly at night
答案
D
解析
文中第三段第二句、三句说:“然而它显示出与生俱来的用星星作导航的能力。装这只鸽子的笼子是被安放在充满人造星星的天空下面。”结合第二段最后一句,“使用人造星星的实验证明:一些长距离飞行的鸟在夜里能够沿着星星的方向飞”。由此我们可以得出选项D正确。其余三个选项均不符合文章内容。
转载请注明原文地址:https://kaotiyun.com/show/D7XO777K
0
在职攻硕英语联考
相关试题推荐
Malnutritionduringweaningage—whenbreastmilkisbeingreplacedbysemi-solidfoods—ishighlyprevalentinchildrenofpoorh
Writeanessayabout200wordsasyouranswertothefollowingquestion:"ShouldtheChinesegovernmentpaymoreattentionandi
ToproducetheupheavalintheUnitedStatesthatchangedandmodernizedthedomainofhighereducationfromthemid1860’stot
Asa______major,heenjoyedworkinginthesteelplant.
Alineinasongasks,"Doesanyonereallyknowwhattimeitis?"Thisquestioncouldeasilyapplytocalendars!Didyouknowth
Asa______actor,hecanperform,sing,danceandplayseveralkindsofmusicalinstruments.
Sequoyahwasbornabout1770inthevillageofTaskigi.HewasaCherokeeIndian,and,alongwithhisentiretribe,hewasillit
Justsevenyearsago,theJarvik-7artificialheartwasbeingcheeredasthemodelofhumancreativeness.ThesightofBarneyCl
Sincethelate1930’stheBureauofIndianAffairsoftheUnitedStateshasbeenworkingtopromotenativelanguageliteracyamo
随机试题
从总体X中抽取样本x1,x2,…,xn,若E(X)=μ,D(X)=σ2,下列统计量中是μ的无偏估计量的为【】
泌尿系感染是脊髓损伤的一个严重并发症,有关脊髓损伤后并发泌尿系感染,以下叙述正确的是
决定方剂功用、主治的主要因素是()
设A是3阶矩阵,P=(α1,α2,α3)是3阶可逆矩阵,且P–1AP=若矩阵Q=(α2,α1,α3),则Q–1AQ=()。[2011年真题]
台湾最大的瀑布是蛟龙瀑布。()
你的职业设计是什么?如果你的职业设计与目前的工作不符,请问你为此做了哪些准备?
调解是指发生纠纷的当事人,在第三者的主持下,互相协商,互谅互让,依法自愿达成协议,使纠纷得以解决的一种活动。下列选项中,属于我国的调解制度的主要有()
网络管理的目标是最大限度地增加网络的可用时间,提高网络设备的利用率,改善网络性能、服务质量和【 】。
Whenshetookamopfromthesmallroomwhatmumreallywantedtodowas______.WhydidmothergotoseeDagmarinthehospita
Inaquaticenvironments,theherbicideatrazineismorelikelyto(i)______developingamphibianswhenitishighlydilutedthan
最新回复
(
0
)