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
A、Six times. B、Five times. C、Three times. D、Two times. B选项表明,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。
A、Six times. B、Five times. C、Three times. D、Two times. B选项表明,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。
admin
2013-09-14
150
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.
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://kaotiyun.com/show/G2c7777K
0
大学英语四级
相关试题推荐
A、Itisverycommonfortheyoungpeopletolivewiththeirparents.B、Peopleusuallygetsickundergreatstrain.C、Thehusband
Forthispart,youareallowed30minutestowriteacompositiononthetopicAJob-searchingExperience.Youshouldwriteatle
ThemainpurposeofthisarticleistohighlypraiseIngridforherdedicationtohercareer.Ingridneverspared______before
TherearemorethanfortyuniversitiesinBritain--nearlytwiceasmanyasin1960.Duringthe1960seight【67】newoneswerefoun
____________________(他想告诉你的是)beforeheleftwasthathehadnevertoldalietoyou.
A、Sheonlyfocusesonfashionandboys.B、Sheonlyfocusesonherstudy.C、Sheonlyfocusesonherfather.D、Sheonlyfocuseson
A、Celsius.B、ClaudiusDay.C、Lupercalia.D、LubricantDay.C此题考查听细节及关键词同义替换的能力,...origianllycalled...与..rootsare...为同义词组及最早的
A、Hecan’tfindgoodexamplestoillustratehispoint.B、Hecan’tfindapeacefulplacetodotheassignment.C、Hedoesn’tknow
Theboy____________(编了个故事);itwasnottrue.
Afterretiringfrom30yearsofteaching,EthbellPeppercouldeasilyhavedecidedtositbackand【B1】______andenjoyapeaceful
随机试题
感染性心内膜炎,最常发生于下列哪种情况如果患者发生猝死,最常见原因是
A.四逆汤B.阳和汤C.理中丸D.当归四逆汤E.小建中汤含有麻黄的是
航标船可以标示出该处的水下深度和暗礁概貌及船只航行的侧面界限,系国家交通运输管理部门为保障过往船只的航行安全而设置的交通设施。2008年3月8日,李某驾驶机动渔船靠近某航标船时,其渔船的螺旋桨被该航标船的钢缆绳缠住使渔船存在翻沉的危险,李某先是尝试持刀砍断
建筑物位于小窑采空区,小窑巷道采煤,煤巷宽2m,顶板至地面27m,顶板岩体重度22kN/m3,内摩擦角34°,建筑物横跨煤巷,基础埋深2m,基底附加压力250kPa,试问,按顶板临界深度法近似评价地基稳定性为下列哪一选项?
质押担保的范围不包括()。
社会工作者小吕最近被机构安排到居家养老服务项目中,让其负责入户探访体弱老人的工作。小吕的督导老蔡有十余年服务老人的经验,在一次督导会谈中示范了接触体弱老人的技巧,包括不时轻轻接触老人的手和肩膀,表达肯定和关怀;说话时语速要慢,语调平缓,句子简单直接;发问时
已知铁与稀硝酸反应生成二价铁或三价铁,同时生成NO,现将14g铁粉溶于1L稀硝酸中恰好完全反应,放出NO气体后称量所得溶液,发现比原溶液质量增加8g,则原溶液中硝酸的浓度是()。
有人认为蜂蜜的用途只是食用,很难想到它还可以美容和做药材。这在心理学上称为()。
假如你是某美国公司的国际业务经理。该公司刚开发了一种新的个人电脑,其功能与现有的电脑相同。但制造成本降低一半。该公司有几项专利可以为这种电脑的独特设计提供保护。首席执行官要求你就在西欧地区的业务扩张提出建议。你的选择是:(1)从美国出口;(2)许可欧洲
管理信息系统开发过程应该遵循信息开发系统的______,但也有其特殊需要考虑的问题。
最新回复
(
0
)