首页
登录
职称英语
The reason why birds don’t get lost on long flights ______. [br] [originaltext]
The reason why birds don’t get lost on long flights ______. [br] [originaltext]
游客
2023-11-14
27
管理
问题
The reason why birds don’t get lost on long flights ______. [br]
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 are 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 had spent his 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.
选项
A、rely on landmarks
B、don’t know which way to fly
C、fly back home
D、wait for the stars to appear
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3184987.html
相关试题推荐
Whatisthethemeoftheforum?[br][originaltext]Aneconomicforum—onO
Thedemonstrationisto______.[br][originaltext]Onthesecondanniversa
Whywasthespeedlimitfirstreducedto55miles-per-hour?[br][originaltext]
Whatarethewaysanimalscommunicate?[br][originaltext]Whenwethinkof
Whatarethewaysanimalscommunicate?[br][originaltext]Whenwethinkof
Whatarethewaysanimalscommunicate?[originaltext]Whenwethinkofcommu
Thetwospeakersaremainlytalkingabout______.[br][originaltext]M:Hi,Jan
WhatdidIndonesiaandAcehrebelsdoonMonday?[originaltext]Indonesiana
WhyAmericanscientistsaredevelopingthesemaps7[br][originaltext]Americ
WhyAmericanscientistsaredevelopingthesemaps7[br][originaltext]Americ
随机试题
[originaltext]M:HeySandra,what’swrong?Youlookfurious!W:I’vehaditwit
[originaltext](5)Anewspeciesofsnakehasbeendiscoveredonaremoteis
______analysisisaprocessofgrammaticalanalysisaccordingtowhichasyntact
Duetopersonality_____,thetwocolleaguesnevergotonwellinwork.(2010-66)A
女性,30岁,烦躁、出汗、消瘦、双手震颤,T、T增高,临床诊断是“甲状腺功能亢进
消化性溃疡发病机制中的防御因子为A.前列腺素E B.酒精 C.Hp感染 D
色彩三要素指()。A.光源色、环境色、固有色 B.红、黄、蓝 C.色相、明
测定长期趋势的方法主要有()。A.回归方程法 B.移动平均法 C.指数平滑法
监理工程师对建设工程施工过程实施监理的主要形式有()。A.颁发证书
人体判断脂肪充实程度最适宜的部位是 A.三角肌B.前臂伸侧下1/3C.上臂
最新回复
(
0
)