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
2023-08-07
51
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.
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、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
短文提到,物体振动得越快,它制造的声音频率就越高。A为录音原文中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/2905729.html
相关试题推荐
[originaltext]Well,forthoseofyouwhohaveseenthepictureinthelittl
[originaltext]Well,forthoseofyouwhohaveseenthepictureinthelittl
[originaltext]IrunadesignstudioinNewYork.Everysevenyears,Iclose
[originaltext]IrunadesignstudioinNewYork.Everysevenyears,Iclose
[originaltext]IrunadesignstudioinNewYork.Everysevenyears,Iclose
[originaltext]AcoupleofweeksagomynephewwentabroadonhispostAlev
[originaltext]AcoupleofweeksagomynephewwentabroadonhispostAlev
[originaltext]ThefirsttimeArnoldSchwarzeneggerwenttotheUnitedState
[originaltext]WhenAshleyBlackmonsatdownforherjobinterviewforamar
[originaltext]W:You’vereadanarticleabouthumanbones.Arethereanycommen
随机试题
[originaltext]W:Themapshowsthatthisstreetgoesdowntown.M:Yes,butwhat
Thereareseveralpossiblerelationshipsbetweenlanguageandsociety.One
信息清理的常用办法有A.双份录入或专人检查 B.目测是否存在相同格式 C.在
薄荷入汤剂应A.另煎 B.布包煎 C.后下 D.先煎 E.冲服
《变电运维管理规定第27分册土建设施运维细则》:严重污秽地区,大门锁孔应加配(
药品行政处罚决定信息公开的范围包括A.行政处罚案件名称、处罚决定书文号 B.违
国家基本药物工作委员会负责A.确定使用国家基本药物目录外药品品种数量 B.制定
治肾气不化,清浊不分所致的白浊,宜选用的成药是A.三金片 B.五苓散 C.肾
根据《标准施工招标文件》(2007年版),下列关于缺陷责任期说法正确的是()。A
A.甲、乙组合 B.乙、丙组合 C.甲、丙组合 D.甲、乙、丙组合
最新回复
(
0
)