首页
登录
职称英语
Why don’t birds get lost on their long flights from one place to another? Scient
Why don’t birds get lost on their long flights from one place to another? Scient
游客
2024-07-19
41
管理
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 blares.
Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly at 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 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. When the stars are hidden by clouds, they apparently 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. [br] 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
见第三段第二句:“Yet it showed an inborn ability to use the stars for guidance其他三项无根据。
转载请注明原文地址:https://tihaiku.com/zcyy/3683627.html
相关试题推荐
Thereasonwhybirdsdon’tgetlostonlongflights______.[br]Theexperiment
Thereasonwhybirdsdon’tgetlostonlongflights______.[br]By"hisoutdoor
Thereasonwhybirdsdon’tgetlostonlongflights______.[br]Duringdaylight
Accordingtothepassage,ifascientistwantstopredictthewayconsumersspen
Ascientistwhowantstopredictthewayinwhichconsumers(消费者)willspend
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothinkthatm
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothinkthatm
Moneymakesmoney.Toputitanotherway,themoreyouinvest,thegreateryour
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Qantas(广达斯航空公司)hasmoreflightstomoreplacesthananyotherAustralianairli
随机试题
Seedcataloguesfeaturehundredsofdifferentfloweringspecies.Fortheper
AfterSusanJoycewaslaidofffromDigitalEquipmentCorp.,shewashorrifi
Youwillnowreadashortpassageandthenlistentoatalkonthesametopic.Y
在IT系统运营过程中,经过故障查明和记录,基本上能得到可以获取的故障信息,接下来
在妇科特殊检查中,用于测定有无排卵的简便方法为A:诊断性刮宫 B:基础性体温测
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性: A.如
下列关于供给价格弹性与供给价格弹性系数的说法,正确的有()。A:供给价格弹性是指
知母与黄柏在大补阴丸的作用是A.滋阴补肾 B.清热生津 C.降泄虚火 D.
自用工之日起一个月内,经用人单位书面通知后,劳动者不与用人单位订立书面劳动合同,
下列各项中,不属于总体应对措施的是()。A.向项目组强调保持职业怀疑的必要
最新回复
(
0
)