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
85
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] 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
谈到动物时,cousins(表兄弟,表姐妹)一词常指它的同类。“his outdoor cousins”意指笼子外的那些鸽子。
转载请注明原文地址:http://tihaiku.com/zcyy/3067364.html
相关试题推荐
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Accordingtoascientificresearch,smokingwill(short)______aperson’slifegr
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Scientistshavediscovered14kindsofvitamins.Ifwedonotgetenoughof
ShesaidshewouldliveinLondonfor______fourorfiveyears.A、anotherB、the
Aguestpayingfullfarecaninviteanotherguesttojointhetourathalfprice
Ifnoonehasany______(object),we’llcontinuetomovetoanotherissue.objec
随机试题
[originaltext]M:Excuseme,haveyougotanybooksonChinesehistory?W:Yes,
Therearepeoplewhoareespeciallyattractedtothenotionof"climbingthe
[originaltext]M:Whatdoyouthinkofmynewsweater,Tracy?W:Well.It’svery
男性,35岁,发热1周伴鼻出血、牙龈出血、球结膜出血及注射部位大片淤斑,血红蛋白
关于金属幕墙防雷装置的说法,正确的是( )。A.防雷装置与主体结构的防雷装置应
JTGD54-2001可以解读为交通运输部公路工程标准D类第5种的第4项标准,破
有一均布荷载作用的简支梁,进行研究性试验时,在短期荷载作用下,实测梁的挠度曲线,
农场养牛工,男,35岁。冬季某日翻倒未充分晒干而有霉变的干草,夜晚咳嗽、胸闷、气
城市控制性详细规划的地形图图纸比例一般为()。A.1:2000~1:500
共用题干 男,14岁。进行性开口困难7年,面部明显不对称。临床检查已完全不能张
最新回复
(
0
)