首页
登录
职称英语
[originaltext] The vast oceans of the world are dark, deep and mysterious plac
[originaltext] The vast oceans of the world are dark, deep and mysterious plac
游客
2023-07-18
85
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 kilometer away. But if a whale shouts in an ocean channel, another whale may hear it tens, if not hundreds, of kilometers 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.
选项
A、Sound travels five times faster through air than through water.
B、Sound travels five times faster through water than through air.
C、Sound travels three times faster through air than through water.
D、Sound travels three times faster through water than through air.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/2846855.html
相关试题推荐
[originaltext]EducationiscompulsoryandfreeforeverychildintheUnite
[originaltext]EducationiscompulsoryandfreeforeverychildintheUnite
[originaltext]Theaveragefamilyspendsaboutonesixthofitsincomeonfo
[originaltext]Theaveragefamilyspendsaboutonesixthofitsincomeonfo
[originaltext]M:Hello,JohnAdamsspeaking.W:Goodmorning,Mr.Adams.Isaw
[originaltext]M:Hello,JohnAdamsspeaking.W:Goodmorning,Mr.Adams.Isaw
[originaltext]M:Hi,Janet.Youaresoluckytobedonewithyourfinalexamsa
[originaltext]M:Hi,Janet.Youaresoluckytobedonewithyourfinalexamsa
[originaltext]W:Oh,Ken,Ihavebeenmeaningtotalktoyou.M:Hi,Denise!Wh
[originaltext]M:Haveyouborrowedyourbooksyet?W:Igotmychemistrybook,
随机试题
Anothercriticalfactorthatplaysapartinsusceptibilitytocoldsisage.
我对他的正直不能信赖。Ihavenorelianceuponhonesty.//Ihavenoconfidenceinhishonest
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
[originaltext]Researchersquestioned580Americansfromages15to26,asw
You’vebeenworkingoutregularlyforquiteawhile,butyou’renowherenear
以下关于疾病保险说法正确的是A.是以约定医疗行为的发生为给付保险金的条件 B.
患者女,50岁。缺失,余牙正常,口底至舌侧牙龈距离为10mm,设计铸造可摘局部义
珍珠的鉴别特征不包括下列哪一项A.质地坚硬,断面可见辐射状纹理,粉性 B.无臭
小潘并非既懂德语又懂法语。如果上述断定为真,那么下列断定必定为真的是( )。A
影响药物胃肠道吸收的因素有A.药物的解离度与脂溶性 B.药物溶出速度 C.药
最新回复
(
0
)