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
2013-06-22
69
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 experiment with the dove indicates that______.
选项
A、birds have to be taught to navigate
B、a bird that has been caged will not fly long distances
C、some birds cannot fly at night
D、some birds seem to follow the stars when they fly at night
答案
D
解析
题干意为“鸽子的实验表明 。”选项A从第三段“But it had an inborn ability to use the stars for guidance.”可以排除。解题关键是从第二段的最后一句话“Tests with artificial stars have proved that certain night—flying birds are able to follow the stars in their long—distance flights.”可排除B、C,并推理出D项为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/YEgK777K
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
Thetravelerthoughtthathe______.Thetravelersaidtohimself,"Ican’tstandthisanylonger"means"______."
Morethanonequestion______asked.
______thereissomethingelsetodiscuss,Iwilldeclarethemeetingclosed.
A、Totheshops.B、Home.C、Toherfriend’shouse.D、Toschool.AM:Dear,canyouwatchthefootballmatchwithme?W:Sorry,Iha
A、Shehasgotadriver’slicense.B、Shewasacceptedbyacollege.C、Sheisgoingtoanothercountry.D、Shegotagoodjob.D从男士
Ourfootballteam______twelvemembers.
Inthefirstsentence,by"this"theauthormeans______.Atfootballmatches,peopleoften______oneteamortheotherbysh
Footballis,Ibelieve,themostpopulargameinEngland:onehasonlytogotooneoftheimportantmatchestoseethis.Richa
Thetwobrotherslookverymuch______.
Theoldladyhas______twowarsandrevolutions.
随机试题
在Excel中,为了形象地表达数据,可以用改变图形的方式任意修改图形,方法是将鼠标移至图表内,单击右键,在快捷菜单中选择(),对图表进行修改。
生物指示剂有芽胞菌片与培养基混合装的指示管。所用生物指示剂中
将0.2mol.L–1的醋酸与0.2mol.L–1醋酸钠溶液混合,为使溶液pH值维持在4.05,则酸和盐的比例应为()。(其中,Ka=1.76×10–5)
煤矿应当建立重点部位巡视检查制度。当接到暴雨灾害预警信息和警报后,对井田范围内废弃老窑、地面塌陷坑、采动裂隙以及可能影响矿井安全生产的河流、湖泊、水库、涵闸、堤防工程等实施()不间断巡查。
在堤防工程的堤身填筑施工中,根据碾压试验确定()等,以保证碾压质量达到设计要求。
背景资料某三级公路地处丘陵地区,砂类土居多,设计车速40km/h,路基宽度8.5m,基层为石灰稳定砂砾,面层为8cm的沥青混凝土。施工过程部分事件摘要如下:事件1:路基施工正好赶上雨期,施工前,施工方做了如下准备工作:(1)住地、库
在会计核算中,一般应通过财产清查进行账实核对。()
矩阵组织形式在()环境中较为有效。
某夜,群众举报张家有人在看黄碟,警察敲门人户后,直接进入张某夫妇的卧室.并没收了VCD和黄碟。关于本案.下列表述不正确的是()。
GRANDAUTOJOURNALTheFirstFedfireAutoRacingCompetitionPublishedquarterlybyAardvarkPublishing,GrandAutoJournaliso
最新回复
(
0
)