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
47
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
[originaltext]W:IsMaryreadytogototheairport?M:Ready?Shehasn’tevenfi
C各项重新变形后,底数为5X1,5X11,5X11X11,5X11X11X11,所以下一项应为5X11X11X11X11,即为C。
妊娠3~5个月胚胎期的主要造血器官是()A.肝 B.脾 C.胸腺
下方分别是一个由长方体堆积而成的立体图形和该立体图形的左视图、后视图,那么该立体
迎香穴位于A.鼻孔外缘,旁开0.5寸 B.鼻翼外缘,旁开0.5寸 C.
A.出血性膀胱炎B.肾脏毒性C.心脏毒性D.过敏反应E.乙酰胆碱综合征环磷酰胺
假定风荷载沿高度呈倒三角形分布,地面处为0,屋顶处风荷载设计值q=134.7kN
(2017年5月)()的首要工作是组织好部门员工实施项目任务和协调上下
(2018年真题)假设其他条件不变,我国东北灾害性天气的出现,将对()期货
甲股份公司共有股权1000万股,为了将来有更好的发展,将80%的股权让乙公司收购
最新回复
(
0
)