首页
登录
职称英语
Why don’ t birds get lost on their long flights from one place to another? S
Why don’ t birds get lost on their long flights from one place to another? S
游客
2024-07-18
6
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 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://tihaiku.com/zcyy/3682164.html
相关试题推荐
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Jacklosthisjobayearagoandhe______anotherjobyet.A、hasfoundB、hasn’t
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Sc
Jacklosthisjobayearagoandhe______anotherjobyet.A、hasfoundB、hasn’tf
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?S
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Sc
Whydon’tbirdsgetlostontheirlongflightsfromoneplacetoanother?Sc
随机试题
【S1】[br]【S8】before→after语义错误。从上句话分析,得知运动爱好者和支持者对世界杯很狂热。所以此句表达的意思应该是在1996年英国获得世
下列因素中属于可变成本的是()。A.机器折旧、租金 B.可以无偿解雇的工人的工
A.吲哚苷 B.醇苷 C.氰苷 D.酚苷 E.酯苷通过酚羟基与糖端基羟基
()是指独立的专家或专家小组或咨询机构作为服务方应受托方的要求,就某一个具体
1999-63.胸闷隐痛,时作时休,心悸气短,倦怠懒言,面色少华,头晕目眩,遇
国民党为维护其反动统治不惜耗资扩充警察机构,同时,设立了庞大的特务机构。(
下列选项中,属于证券投资基金按投资对象分类的是()。 A.公司型基金B.契
下列各项中,属于企业采用市场渗透战略的有( )。A.甲餐饮公司为了把控餐饮食材的
注册会计师执行财务报表审计遇到下列情形,其中可能在发表的审计报告中增加其他事项段
ISO9000质量管理体系中,质量管理原则之一是要求以顾客为关注焦点,这里的顾客
最新回复
(
0
)