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
68
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
At4:30inthemorningonApril12,1861,theonlywarbetweenthesouthandthenorthinthe【11】oftheUnitedStatesbegan.Aft
July24,2005DearHospitalAdministrator,Lastmonth,mydaughterSusanwasinyourhospitalforthreedayswhenshehadher
A、Inthehospital.B、Atwork.C、Athome.D、Intheoffice.A对话中,男士询问女士是否感觉好些了(feelbetter),女士表示他开的药非常有效(useful)。从这样的信息可以看出,此对话很可能
Theroadwasunderrepairsowehadtogoround.
A、Atthebookstore.B、Atthelibrary.C、Atthetravelagency.D、Atthehospital.B在这段对话中,男士询问这些书可以借多久?女士告诉他是两个星期,而且提示如果超期要被罚款(
Therearequitealotof(different)______betweenthetwobrothers.
Thebrokenbikeneeds(repair)______.
A、Iworkhard.B、I’mdancing.C、I’vegotaheadache.D、Ilikeswimming.C问题为“你怎么啦?”四个选项中只有C“我头疼”是合适的回答,故选C。
Bothofthetwinbrothers(be)______capableofdoingtechnicalworkatpresent.
A、Iworkhard.B、I’mdancing.C、I’vegotaheadache.D、Ilikeswimming.C问题为“你怎么啦?”四个选项中只有C“我头疼”是合适的回答,故选C。
随机试题
男性,40岁,慢性咳嗽、咳痰病史近20年,早晚咳痰重,痰量多,无吸烟史,近1周来发热,咳黄色脓痰,时有痰中带血,每日痰量约300ml。查体:杵状指,左肺底可及固定性大水泡音。该患者首先应该考虑的疾病诊断是
根据《建设工程工程量清单计价规范》GB50500—2013,适宜采用综合单价法计价的措施项目费是()。
瓦格纳不认为财政支出规模不断扩大是由于()。
商务谈判中的谈判班子人员构成应()。
评估信度的方法主要包括()。
下列文字中画横线部分存在错误的是()。古代的东西方商路主要有三条:一条是从中亚由陆路沿里海、波罗的海(A)到小亚细亚;一条是先由海路至波斯湾,然后经两河流域到地中海东岸(B)的叙利亚一带;第三条是先由海路至红海,然后再由陆路到埃及(C)的亚历山大
关于OSPF路由协议的说法中,正确的是__________。
(68)不是通信协议的基本元素。
有以下程序:#includemain(){intx=1,y=0;if(!x)y++;elseif(x==0)if(x)y+=2;elsey+=3;printf(“
A、 B、 C、 D、 DDBA(数据库管理员)的主要工作可以概括为3种:①数据库设计;②数据库维护;③改善系统性能,提高系统效率。
最新回复
(
0
)