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
2024-07-23
52
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] By "his outdoor cousins" the author means______.
选项
A、other experimenters
B、the other doves of the same brood
C、doves under the natural sky
D、other birds in general
答案
C
解析
A项“其他实验者”;B项“其他同一窝的鸽子”;C项“在自然天空下飞行的鸽子”;D项“其他鸟类”。根据题意,C为正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3689765.html
相关试题推荐
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Thereasonwhybirdsdon’tgetlostonlongflights______.[br]Duringdaylight
Itisa(regret)______thingtomakeanotherpersonsuffer.regretful
Moneymakesmoney.Toputitanotherway,themoreyouinvest,thegreateryour
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Qantas(广达斯航空公司)hasmoreflightstomoreplacesthananyotherAustralianairli
Whatmakesonepersonmoreintelligentthananother?Whatmakesonepersona
ThereisanothersalethisChristmasseason.Withtheslidingsoundofcash
Jacklosthisjobayearagoandhe______anotherjobyet.[originaltext]时态[/ori
随机试题
•ReadthispartofafaxfromSallySaunders,ahotelconferencemanager.
OnSeptember13,theNewYorkCityHealthDepartmentbecamethefirstinthe
PassageTwo[br]Asitmentionedinthepassage,whosevacuumcleanerinvolvedt
[originaltext]CountyfairsareatraditioninNewEnglandtowns.Theyoffer
TheconstructionoftheWhiteHousebeganin1792,butitwasnotcompleted
2017年1月1日,甲企业购入一项无形资产并投入使用,初始入账价值为100万元,
中国证监会设私募基金监管部,其职能是() Ⅰ.拟定私募投资基金合格投资者标准
关于结核病的治疗,哪项错误A.应坚持早期、联合、大量、规律和全程用药 B.有结
黄昏了。慢慢地,像是偷偷地走着,紫丁香色的阴影落了下来,罩着森林。巨大的日轮在
根据《建筑工程建筑面积计算规范》(GB/T50353-2005),不应计算建筑面
最新回复
(
0
)