首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
专升本
Why don’t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for many ye
Why don’t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for many ye
admin
2011-03-26
105
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 blanks.
Not long age, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly by 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 (鸽子) 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. (76)
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.
(77)
But the stars are apparently their principal means of navigation (航行) only.
When the stars are hidden by clouds, they seemingly 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.
During daylight hours, birds ______.
选项
A、wheel back and forth
B、follow the stars in their flights
C、use sun for guidance
D、are quite likely to get lost
答案
C
解析
见第二段、中句子“…experiments showed that birds rely on the sun to guide them during daylight hours”。
转载请注明原文地址:https://kaotiyun.com/show/34vC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
阅读钱钟书《论快乐》中的一段文字,然后回答下列小题。“永远快乐”这句话,不但渺茫得不能实现,并且荒谬得不能成立。快过的决不会永久:我们说永远快乐,正好像说四方的圆形、静止的动作同样地自相矛盾。在高兴的时候,我们的生命加添了迅速,增进了油滑。像浮士德那样,
Mostpeople______.Monkeys______.
ThebabywassenttoahospitalinLondonbecause______.Fromthispassageitseemsthatthebaby’sillnesshadsomethingtod
InAncientGreecelivedayoungmancalledNarcissus,whowasgreatly【B1】,forhewasveryhandsome.Narcissuswasveryproud
Inolddays,whenaglimpseofstockingwaslookeduponassomethingsoshockingastodistracttheseriousworkofanoffice,s
Thewindisblowinghard;(pleaseseethatallthewindowsarefastenedproperly).
Independentschoolsareactuallycalled______.Mostoftheindependentsecondaryschools______.
You(本来应该)finishedthistaskabitearlier.
ThelibrarianinsiststhatJohn_____nomorebooksfromthelibrarybeforehereturnsallthebookshehasborrowed.
Theydidn’ttellme______gofortheirholiday.
随机试题
下列属于观赏泉的是()。
我国最著名的红树林海岸在()。
每年的11月14日是联合国糖尿病日,是由世界卫生组织和国际糖尿病联盟共同发起的,其宗旨是引起全球对糖尿病警觉和醒悟。以下属于糖尿病的症状的是()。
1,1,5,3,9,9,13,27,(),()。
该市1950年轻工业比重占多少?( )该市三十年来轻工业比重增加多少?( )
FemaleBullfightingItwasaunique,eye-catchingsight:anattractive,womaninashinybullfighter’ssuit,swordinhand,
Howmuchwillthewomanhavetopayifshebuytwoshirts?
•Yourcompanyrequiresnewofficeandwarehousepremises.Youhavebeenaskedtolookattwoofficeandwarehouseproperties,a
Itisabsurdthatone______possesstwofreezersintheroom.
Inmanycountries,governmentsaretryingtogetcitizenstoeatmorehealthily.Onewayinwhichgovernmentsaretryingtodot
最新回复
(
0
)