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
2023-10-02
27
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 reasons why birds don’t get lost on their long flights_______.
选项
A、have been known to scientists for years
B、have only recently been discovered
C、are known by everyone
D、will probably remain a mystery
答案
B
解析
题干意为“在长途飞行过程中鸟儿不会迷路的原因______。”从文章第一段最后一句话“Now they’re starting to fin in the blanks.”可以得出答案B。A项“科学家们已经掌握多年了”;C项“每个人都知道”;D项“将有可能继续是一个谜”,都不符合文意。
转载请注明原文地址:https://tihaiku.com/zcyy/3064637.html
相关试题推荐
(give)______anotherchance,IamsureIcandoitbetter.Given。本句非谓语动同短语在句中作状语
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Thereasonwhybirdsdon’tgetlostonlongflights______.[br]Intotaldarkne
Thereasonwhybirdsdon’tgetlostonlongflights______.[br]Theexperiment
Moneymakesmoney.Toputitanotherway,themoreyouinvest,thegreateryour
NotonlyIbutalsoJaneandMaryaretiredofhavingonemeetingafteranother.
Whatmakesonepersonmoreintelligentthananother?Whatmakesonepersona
ThereisanothersalethisChristmasseason.Withtheslidingsoundofcash
随机试题
Ihada【16】d______timelastyearwithmyhealth.ForseveralmonthsI【17】su
______isthecapitalcityofNewZealand.A、WellingtonB、VancouverC、AucklandD、C
TheUnitedStates’predominanceinscienceandtechnologyisfading,arepor
上述属于丙类传染病的是A.鼠疫、炭疽B.艾滋病、炭疽C.狂犬病、麻风病D.猩红热
适合反映2011年我国城镇和农村消费支出结构情况的图形是()。A.环形图
A.相反B.相使C.相畏D.相杀E.相恶生姜能减轻或消除生半夏的毒性,属于
景观要素包括自然景观要素和人工景观要素,下列属于自然景观的有( )。A.公园
刘先生,40岁,住院烧伤科,左前臂Ⅱ度烧伤5天,局部创面湿润、疼痛。可在局部进行
土的渗透变形形式的确定方法为()。A.只有依据现场试验确定 B.只有依据室
民事法律行为的委托代理,可以用书面形式,也可以用口头形式。()
最新回复
(
0
)