首页
登录
职称英语
Why don’ t birds get lost on their long flights from one place to another? S
Why don’ t birds get lost on their long flights from one place to another? S
游客
2023-10-05
30
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 a long time. Now they’ re starting to fill in the blanks.
Not long ago, experiments showed that birds use the sun to guide them during daylight hours. How do birds 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. But it had 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 main means of navigation. When the stars are hidden by clouds, they apparently find their way by such landmarks as river courses, mountain ranges, coast lines. But when it’ s too dark to see these things, the doves circle helplessly, unable to find their way. [br] During daylight hours, birds______.
选项
A、fly aimlessly
B、rely on landmarks
C、rely on the sun for guidance
D、are more likely to get lost
答案
C
解析
题干意为“在白天,鸟儿______。”A项“漫无目的地飞行”;B项“依靠路标”;C项“使用太阳导航”;D项“很有可能迷路”。从文章第二段第一句话“Not long ago,experiments showed that birds use the sun to guide them during daylight hours.”可以判断C为正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3073502.html
相关试题推荐
Atonetimeoranotherwehaveallstoppedtothinkabouttheweather.Somed
[originaltext]M:Howlongisthetrip?W:It’s17hourstoParisandanother6
WhatisHeavenair?______[br]MostflightsofHeavenAirgoto______.A、small
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Allflights______becauseoftheheavysnow,wehadtotakethetrain.A、werecanc
______anotherchance,Iwillcertainlypassthedrivingtest.A、GiveB、TogiveC、
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
ShesaidshewouldliveinLondonfor______fourorfiveyears.A、anotherB、the
All______toHongKongweredelayedbecauseofbadweather.A、flyB、flightsC、flyi
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
随机试题
中国的重阳节(DoubleNinthFestival)由来已久。人们普遍认为重阳节源于“辟邪”(wardingoffevil).这一天的活动,包
Ialwaysthinkofbookswithunutterablefeelings,beingdeeplyindebtedtothem
[originaltext]M:Thenewmayorisreallyagoodpublicspeaker.Thespeechhed
并联电容器组运维细则中,正常情况下电容器的投入、切除由调控中心AVC系统自动控制
运行中干式电抗器发生下列情况时,应立即申请停用,停运前应远离设备:接头及包封表面
下图是一块前后两面临街的矩形土地,总深度为30.00m,前街路线价(土地单价)为
平面四连杆机构ABCD如图所示,如杆AB以等角速度ω=1rad/s绕A轴顺时针
多基原的药材有A.红花 B.菊花 C.山银花 D.辛夷 E.丁香
女性,25岁。左耳垂下有时大时小的肿块6年,检查见:左耳垂下可见一个2×2cm的
下列工程所需的有关建筑材料、建筑构配件和设备,工程设计单位可以指定相应的生产厂、
最新回复
(
0
)