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
65
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] The experiment with the dove indicates 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
题干意为“鸽子的实验表明 。”选项A从第三段“But it had an inborn ability to use the stars for guidance.”可以排除。解题关键是从第二段的最后一句话“Tests with artificial stars have proved that certain night—flying birds are able to follow the stars in their long—distance flights.”可排除B、C,并推理出D项为正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3073504.html
相关试题推荐
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Sc
Atonetimeoranotherwehaveallstoppedtothinkabouttheweather.Somed
Anothersolutionwasforthem(take)______chargeofitjointly.totake不定式通常含有“
Thepilotwillbeabletoseeonthescreenwhetheranotherplane’scourseconfl
WhatisHeavenair?______[br]MostflightsofHeavenAirgoto______.A、small
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Allflights______becauseoftheheavysnow,wehadtotakethetrain.A、werecanc
ShesaidshewouldliveinLondonfor______fourorfiveyears.A、anotherB、the
All______toHongKongweredelayedbecauseofbadweather.A、flyB、flightsC、flyi
随机试题
Themovieis________boring:itis,infact,ratherexcitingandinteresting.A、an
过多的计算机设备低效率的使用可以通过哪种方法得到控制?()A.应急计划 B
妊娠腹痛血虚证的治法是A.疏肝解郁,养血安胎 B.暖宫止痛,养血安胎 C
ELISA不可应用于下列哪一方面检测A.病原体的检测 B.抗体的检测 C.肿
铁心对地绝缘电阻测试应采用()V兆欧表测量,持续时间为1min,应无闪络及击穿现
下列房地产市场预警指标中,属于考察房地产价格是否过度偏离其价值的是()。A.住
Iftheexchangeratewiththedollarcon
下列计价方法中,属于建设投资估算编制方法的是()。A.预算定额法 B.资金周转
施工企业采购的某建筑材料出厂价为3500元/吨,运费为400元/吨,运输损耗
女,6岁。发热2周,轻咳,精神差,一直抗生素静脉治疗,仍发热。近2日诉头痛,时有
最新回复
(
0
)