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
外语
Why don’ t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for a long
Why don’ t birds get lost on their long flights from one place to another? Scientists have puzzled over this question for a long
admin
2015-01-10
40
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.
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 fill 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://jikaoti.com/ti/zToMFFFM
本试题收录于:
大学英语三级B级题库大学英语三级分类
0
大学英语三级B级
大学英语三级
相关试题推荐
WhatadvicedodoctorsgiveaboutvitaminC?DoctorsrecommendvitaminCto______.Howcanyouprotectotherpeoplewhenyou
A、Thankyou.B、Fine.C、Really?D、Itsoundsnice.AThankyou可以回答一切恭维语。
AdvertisementAGroupProductManagerThisisarareopportunitytoworkataseniorlevelforamarketleaderinthefoodindu
Whenwillthenewpricetakeeffect?On______.What’sthepurposeoftheletter?Toinformthecustomerof______.
A—actionadvertisingB—airportadvertisingC—billboardadvertisingD—businessadvertisingE—directmailadvertising
Themanageraskedthateachemployee(hand)______inareportbeforeWednesday.
MostAmericanswon’tbetreatedespeciallyrespectfulbecauseoftheirageorsocialrank,theywillfeel______.Whichoffoll
Accordingtothewriter,greetingssuchas"Howdoyoufeel?"_____Thequestion"Howdoyoufeel?"seemstobecorrectandsui
FromthefirstletterwelearnthatMary______.Whenhavingdinner,theguestsareexpectedto______.
Ifyouworkfrom9:00a.m.to4:30p.m.everyday.Whichschoolwillyouchoose?IfyoutaketheeveningclassesattheInterna
随机试题
X线照片影像的五大要素不包括
处理空气栓塞者的方法有
A.清热解毒B.疏风清肺C.清热除湿解毒D.清热除湿,活血散结E.除湿化痰,活血散结痤疮,痰湿瘀滞证的治法是()。
以下表述正确的有()。
票据的流通性是指()。
某通讯公司是一家正在高速发展的公司,由于市场份额不断扩大,人手不足,导致大量有价值的客户严重流失,人才短缺已经成为公司发展的主要障碍。因此,公司非常重视员工的选聘与培训工作。该公司对应届毕业生特别是重点院校毕业生的招募给予足够的关注。公司人力资源部
根据《村民委员会选举法》,提名权是直接提名村民委员会成员候选人的权利。直接提名不包括()。
人们创造历史的第一个或最基本的活动是物质资料生产活动。()
Hesaidthatbookson______popularsciencearein______shortsupply.
Ican______thehousebeinguntidy,butIhateitifit’snotclean.
最新回复
(
0
)