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
2023-08-29
25
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. [31]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.
29. What is the relationship between the vibration of an object and the frequency of its sound?
30. What sounds can humans hear?
31. 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/2968601.html
相关试题推荐
[originaltext]Thecostisgoingupforjustabouteverything,andcolleget
[originaltext]W:Howareyoudoing,Christopher?M:Tobehonest,I’mreallyfe
[originaltext]W:Howareyoudoing,Christopher?M:Tobehonest,I’mreallyfe
[originaltext]W:Howareyoudoing,Christopher?M:Tobehonest,I’mreallyfe
[originaltext]M:I’mplanningtobuyahouse,andI’dliketofindoutabouta
[originaltext]M:Whyareyouleavingsoearly?Themoviedoesn’tstarttillsev
[originaltext]M:Whyareyouleavingsoearly?Themoviedoesn’tstarttillsev
[originaltext]M:Whyareyouleavingsoearly?Themoviedoesn’tstarttillsev
[originaltext]Yearsagobeforetherewererefrigerators,anicehousewasab
[originaltext]M:Oneofthemostcommonquestionsweaskaboutpeople’sbehavio
随机试题
Acompanyhaslaunchedrevolutionarysoftwarefortrackingstolenmobilepho
【B1】[br]【B9】[audioFiles]audio_eusm_j01_168(20099)[/audioFiles]Ifso,thenwet
【B1】[br]【B2】A、owingB、accordingC、connectingD、asC此处的选项需要和to搭配。[A]owingto表示“
国家规定的五种三相变压器标准连接组别是:Y/Y0-0,Y/Δ-ll,Y0/Δ-l
图示多跨梁C截面的弯矩为( )。 A、M/4 B、M/2 C、3M/4
任何金融产品或服务的卖点均可以从()方面进行概述。A.安全性 B.灵活性
下列会计事项中,会引起留存收益总额发生增减变动的是()。 Ⅰ收到投资者
分类分项工程量清单项目编码500101002001中的后三位001代表的含义是(
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性:
(2015年真题)关于建设项目竣工运营后的新增资产,下列说法中正确的是()
最新回复
(
0
)