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
2023-10-03
60
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:http://tihaiku.com/zcyy/3067365.html
相关试题推荐
______anotherchance,Iwillcertainlypassthedrivingtest.A、GiveB、TogiveC、
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Scientistshavediscovered14kindsofvitamins.Ifwedonotgetenoughof
Scientistshavediscovered14kindsofvitamins.Ifwedonotgetenoughof
ShesaidshewouldliveinLondonfor______fourorfiveyears.A、anotherB、the
Ifnoonehasany______(object),we’llcontinuetomovetoanotherissue.objec
Scientistsareeagertotalkwithotherscientistsworkingonsimilarproblems.
Itisa(regret)______thingtomakeanotherpersonsuffer.regretful
随机试题
(1)ConservationistsonTuesdayappealedtocountriestourgentlyaddressnew
[originaltext]Onewinterdayin1891,aclassatatrainingschoolinMassa
下列内容中,哪一项是设计概算主要编制依据?()A.项目建议书 B.方案招标
急腹症病人腹腔内穿刺液为带臭味的血性液,最可能为()A.肠套叠 B.胆囊
呕吐呈喷射状者多为A、脾胃阳虚 B、热扰神明 C、食滞胃脘 D、饮邪犯胃
患者,女性,70岁。住院心电图监测时发生室性心动过速,心率172次/分,血压12
下列各项中,不符合内部牵制的要求的是()。A、出纳人员管票据 B、出纳人员
急性细菌性肺炎的首选治疗药物是()。A.青霉素 B.阿司匹林 C.氧氟沙星
遵义会议之前,中共中央曾经先后出现过的“左”倾错误有( )。A.瞿秋白盲动主义
在MMPI及MMPI-2剖面图中,如果6、8量表T分均升高,F量表T分也超过7
最新回复
(
0
)