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
2024-03-08
4
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. [9] 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. [10] 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. [11] 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. [11] 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.
9. What is the relationship between the vibration of an object and the frequency of its sound?
10. What sounds can humans hear?
11. According to the speaker, what is the phenomenon of echolocation?
选项
A、Those with frequencies lower than 20 hertz.
B、Those with frequencies about 21,000 hertz.
C、Those with frequencies lower than 20,000 hertz.
D、Those with frequencies higher than 20,000 hertz.
答案
C
解析
录音提到,人类可以听见频率在20赫兹到2万赫兹之间的声音。由此可知,C为正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3516333.html
相关试题推荐
[originaltext]Thereissomethingaboutwaterthatmakesitagoodmetaphor
[originaltext]Thereissomethingaboutwaterthatmakesitagoodmetaphor
[originaltext]Inthisweek’seditionofspecialseriesonBizarreMedical
[originaltext]Thereissomethingaboutwaterthatmakesitagoodmetaphor
[originaltext]Thereissomethingaboutwaterthatmakesitagoodmetaphor
[originaltext]Inthisweek’seditionofspecialseriesonBizarreMedical
[originaltext][12]Agooddoseofwillpowerisoftennecessarytoseeany
[originaltext][12]Agooddoseofwillpowerisoftennecessarytoseeany
[originaltext][12]Agooddoseofwillpowerisoftennecessarytoseeany
[originaltext][12]Agooddoseofwillpowerisoftennecessarytoseeany
随机试题
[originaltext]AnewreportfindsthatWestAfricahasbecomeamajorhubof
患儿男,1岁,因剧烈腹泻蛋花水样便入院,查体:前囟眼窝明显凹陷,四肢凉,脉细弱,
体育课程实施过程中人力资源的开发主要包括体育教师、( )、有体育特长的教师、卫
信息披露义务人,是指( )。 Ⅰ股权投资基金管理人 Ⅱ股权投资基金托管人
以小腹胀满疼痛,小便涩滞,淋漓不宣为特征的病证是A.热淋 B.血淋 C.石淋
《变电检测管理规定第6分册铁心接地电流检测细则》:变压器铁心接地电流检测,在变压
关于SWOT分析方法解释正确的是( )。A.S是指企业内部优势 B.W是指企
下列哪项表现为呼吸急促似喘,喉间有哮鸣音A.少气 B.哮 C.气粗 D.短
某公司在新员工甄选过程中采用了人格测试,要求求职者基于自身感受实事求是地填答一套
隧道钻爆法开挖时,炮眼根据围岩的好坏、施工方法的快慢来确定炮眼深度,一般在100
最新回复
(
0
)