首页
登录
职称英语
[originaltext] The vast oceans of the world are dark, deep and mysterious pl
[originaltext] The vast oceans of the world are dark, deep and mysterious pl
游客
2024-02-08
7
管理
问题
The vast oceans of the world are dark, deep and mysterious places where eyesight counts for little as soon as you venture very far beneath the surface.
For humans, who live in a world dominated by visual stimuli, to exist in such conditions would be impossible. But for whales and dolphins that live in the ocean or, in the case of a few species, muddy rivers, the darkness is unimportant. What is important to them is sound.
Sound is an efficient way to transmit and sense information, especially as it travels five times faster through water than through air. If humans shout to someone, it is unlikely that they will be heard a kilometre away. But if a whale shouts in an ocean channel, another whale may hear it tens, if not hundreds, of kilometres away.
Whales and dolphins use sound in two ways: for communication and for echolocation. Dolphins and toothed whales communicate through a wide variety of high-frequency sounds.
But as well as using sounds to communicate, toothed whales and dolphins also rely on echolocation to learn about their immediate environment, including prey that might be waiting nearby. They produce intense short broad-band pulses of sound in the ultrasonic range. These clicks are brief, typically less than one millisecond long — but they are repeated many times each second.
Questions 16 to 18 are based on the passage you have just heard.
16. For whales and dolphins, which sense is most important?
17. How much faster does the sound travel in the water than in the air?
18. How do the dolphins and toothed whales communicate?
选项
A、Six times.
B、Five times.
C、Three times.
D、Two times.
答案
B
解析
选项的内容表明,本题考查倍数或次数。短文中提到,声音在水中传播的速度是在空气中传播速度的5倍,故答案为B)。数字处为常考点,是听音重点。
转载请注明原文地址:https://www.tihaiku.com/zcyy/3433065.html
相关试题推荐
[originaltext]WhenJustinBassettinterviewedforanewjob,heexpectedth
[originaltext]WhenJustinBassettinterviewedforanewjob,heexpectedth
[originaltext]"TheSanFranciscoBayAreaistheplaypenofcounterculture,
[originaltext]Sayyougetintobed,preparedforahealthysevenoreighth
[originaltext]W:Youdon’tlooktoowell.Maybeyoushouldtakethedayofffro
[originaltext]W:Youdon’tlooktoowell.Maybeyoushouldtakethedayofffro
[originaltext]W:Youlookbettertoday.Howdidyourtestgo?M:Muchbetterth
[originaltext]W:Youlookbettertoday.Howdidyourtestgo?M:Muchbetterth
[originaltext]W:Youlookbettertoday.Howdidyourtestgo?M:Muchbetterth
[originaltext]M:StevenHawkingwarnsthathumanswillhavetomovetootherpl
随机试题
Housingofficialssaythatlatelytheyarenoticingsomethingdifferent:stu
Whatisthispassageabout?[originaltext]Indiaisthelandoffestivals.D
High-qualitycustomerserviceispreached(宣扬)bymany,butactuallykeepingc
[audioFiles]audio_eusm_j01_281(20099)[/audioFiles]A、Beforedinner.B、Rightafte
电缆隧道除在进入建筑物处,以及在变电所围墙处应设带门的防火墙外,并应每隔多少m距
A本题考查计算机系统逻辑运算基础知识。
AA BB CC DD
某市2009年底进行棚户区改造。房屋拆迁补偿方式,棚户区业主可以选择房屋产权
自我效能感的功能有() A.决定人们对活动的选择 B.影响人们对该活动的坚
(2018年真题)许多企业在“5S”管理基础上增加了节约和()两个活动,构成了
最新回复
(
0
)