首页
登录
职称英语
[originaltext] Why don’t birds got lost on their long migratory flights? Sci
[originaltext] Why don’t birds got lost on their long migratory flights? Sci
游客
2023-07-12
44
管理
问题
Why don’t birds got lost on their long migratory flights? 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 mainly by night? Tests with artificial stars have proved conclusively that certain night-flying birds are able to follow the stars in their long-distance flights.
One such bird—a warbler—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 at migration time. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the make-believe stars caused a change in the direction of his flight.
Scientists think that warblers, when flying in daylight, use the sun for guidance. But the stars are apparently their principal means of navigation. What do they do when the stars are hidden by clouds? Apparently, they find their way by such landmarks as mountain ranges, coast lines, and rivet courses. But when it’s too dark to see these, the warblers circle helplessly, unable to get their bearings.
选项
A、Birds have to be taught to navigate.
B、A bird that has been caged will not.
C、Some birds cannot fly at night.
D、Some birds seem instinctively to follow the stars when flying at night.
答案
D
解析
What do we learn from the experiment with the warbler?
转载请注明原文地址:https://tihaiku.com/zcyy/2829303.html
相关试题推荐
[originaltext]Oneimportantcauseofthegenerationgapistheopportunity
[originaltext]Oneimportantcauseofthegenerationgapistheopportunity
[originaltext]Oneimportantcauseofthegenerationgapistheopportunity
[originaltext]About1in20adultsintheUnitedStatescannotreadEnglish.A
[originaltext]W:(22)Dr.White,werecentlylearnedthatalargepieceoftheL
[originaltext]W:Sam,couldyoureviewtheresultsofthesurveyonleisurespo
[originaltext]W:Sam,couldyoureviewtheresultsofthesurveyonleisurespo
[originaltext]W:Sam,couldyoureviewtheresultsofthesurveyonleisurespo
[originaltext]Whydowecry?Canyouimaginelifewithouttears?Notonlyd
[originaltext]Whydowecry?Canyouimaginelifewithouttears?Notonlyd
随机试题
[originaltext]W:Whyisthereabigsignonthebackofyourdoorthatsays"ke
Chinahasoutlinedanewapproachtoforeigninvestment,withplannerssayin
某储运公司仓储区占地300m×300m,共有8个库房,原用于存放一般货物。3年前
下列关于平板玻璃的特性说法,不正确的有()。A:良好的透视、透光性能 B:隔
患者,女,30岁。排便时肛门部剧痛,并有少许鲜血滴出1周,疼痛于排便后约20分钟
越鞠丸所治的"六郁"证不包括A.痰郁 B.寒郁 C.食郁 D.火郁 E.
小华认为法律或道德是一种社会契约,根据柯尔伯格的道德发展理论,小华的道德判断属于
中国证监会发布的《上市公司行业分类指引》把上市公司按()级进行分类。A:一 B
2017年末,全国收费公路里程16.37万公里,约占公路总里程的3.43%。其中
共用题干 一般资料:李某,男性,26岁,无业。案例介绍:李某在母亲陪同下前来。
最新回复
(
0
)