首页
登录
职称英语
Why don’t birds get lost on their long flights from one place to another? Sc
Why don’t birds get lost on their long flights from one place to another? Sc
游客
2023-10-01
51
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/3061948.html
相关试题推荐
Whatmakesonepersonmoreintelligentthananother?Whatmakesonepersona
Jacklosthisjobayearagoandhe______anotherjobyet.[originaltext]时态[/ori
Canadaislargerthan______countryinAsia.A、anyB、anyotherC、otherD、another
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Scient
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Scient
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Jacklosthisjobayearagoandhe______anotherjobyet.A、hasfoundB、hasn’tf
Jacklosthisjobayearagoandhe______anotherjobyet.A、hasfoundB、hasn’t
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Sc
随机试题
CustomersarereluctanttobuytheproductmadebyTBMCompany,butthereappear
_____,hedoesgetirritatedwithhersometimes.A、AshelikesherB、Nowthathe
Aninternationalcommitteeofdoctorssaysthatthenumberofcasesofbrain
ThePlaceWherethePoorOnceThrivedA)Thisistheland
对于皮脂腺囊肿合并感染的治疗,下列说法恰当的是A.将囊内容物清除 B.仅切除囊
被称为"后天之本"的脏是()A.肾 B.脾 C.肝 D.肺 E.心
龟甲入汤剂应当A.包煎 B.先煎 C.后下 D.另煎 E.烊化
治疗肾精薄弱证胎怯应首选的方剂是A.补肾地黄丸 B.六味地黄丸 C.金
在物料提升机(龙门架、井字架)的安全控制要点中,钢丝绳端部的固定当采用绳卡时,绳
中、晚期原发性肝癌最常见的主要体征是 A.黄疸B.肝肿大C.脾肿大D.右
最新回复
(
0
)