首页
登录
职称英语
[originaltext] Objects that are vibrating make sounds. Rhythmic sound vibrat
[originaltext] Objects that are vibrating make sounds. Rhythmic sound vibrat
游客
2023-08-21
28
管理
问题
Objects that are vibrating make sounds. Rhythmic sound vibrations produce sound waves which travel in every direction. The frequency of a sound is the number of waves that pass a given point each second.The more rapidly an object vibrates, the greater the frequency of sound it makes. Frequency is measured in hertz. One hertz equals one sound wave per second. The frequency of sound determines the degree of highness or lowness of the sound. A high-pitched sound has a higher frequency than a low-pitched sound.Humans hear sounds that have frequencies from about 20 hertz to 20,000 hertz. Sound with a frequency higher than 20,000 hertz is called ultrasound which is too high-pitched for humans to hear. However, many animals can hear ultrasound. Bats can hear higher sounds than any other animal. Some can hear up to 210,000 hertz. Bats send out lots of high-pitched squeaks and then listen to the echoes bouncing off things like insects. The shorter the time interval between the squeak and the echo, the closer they are to the insect. Using sound to find or "see" things is called echolocation. Another animal that uses ultrasound is the dolphin. Dolphins can hear sounds up to about 150,000 hertz. Dolphins use sound waves to find food underwater.They make clicking sounds that hit whatever is around them and then bounce back to the dolphins. Dolphins can send as many as 2,000 clicks per second. Dolphins’ ultrasound ability is so sensitive that they can detect small fish from 10 feet away.
19. What is the relationship between the vibration of an object and the frequency of its sound?
20. What sounds can humans hear?
21. According to the speaker, what is the phenomenon of echolocation?
选项
A、The quicker it vibrates, the greater the frequency of sound it produces.
B、The slower it vibrates, the higher the frequency of sound it produces.
C、The quicker it vibrates, the lower the frequency of sound it produces.
D、The frequency of sound it produces is not in proportion to the speed it vibrates.
答案
A
解析
细节题。短文提到,物体振动得越快,它制造的声音频率就越高。A为原文中the more…the greater结构的同义表达,故为正确答案。B与C意思相同,可同时排除;D明显与原文内容相冲突。
转载请注明原文地址:https://tihaiku.com/zcyy/2945576.html
相关试题推荐
[originaltext]W:Doyouwantmetoexplainthesequestionsbeforemeexam?M:
[originaltext]MySpace,thesocialnetworkingwebsite,isdifferentfromoth
[originaltext]I’dliketosharewithyoutodaymyexperiencewithanewapp
[originaltext]I’dliketosharewithyoutodaymyexperiencewithanewapp
[originaltext]I’dliketosharewithyoutodaymyexperiencewithanewapp
[originaltext]Theflag,themostcommonsymbolofanationinthemodernwo
[originaltext]Theflag,themostcommonsymbolofanationinthemodernwo
[originaltext]M:Nextmonthyou’regoingtocelebrateThanksgivingDay.Whenis
[originaltext]W:I’msorry,Mike.Ihavetoputoffourmeetingtillfouro’clo
[originaltext]W:I’msorry,Mike.Ihavetoputoffourmeetingtillfouro’clo
随机试题
Atatimewhentheworldisshortofcausesforcelebration,hereisacandi
中国共产党第十九届中央委员会第二次全体会议,于2018年1月18日至19日在北京
下列各项中,一般不作为以成本为基础的转移定价形式的是()。A.完全成本 B.固
承担农民工子女义务教育责任的主体是()。A.输出地政府 B.输入地政府 C
根据《房屋建筑与装饰工程工程量计算规范》GB50854—2013规定,关于屋面防
企业采购部门根据采购申请单制定的,并交给供应商作为订货依据的具有法律效力的书面文
据《论语》所载,孔子教人,“不愤不启,不悱不发”,后《学记》又提出“道而弗牵,强
有同事传话,说公司有位副总有事找你,你问同事副总找自己有什么事,他说“副总没说
当事物处在量变状态时,()。A.事物处在数量上的增减变化 B.事物表现为平衡和
累计凭证是在一定期间内根据多张相同的原始凭证累计而成。()
最新回复
(
0
)