问题 选择题

将耳朵贴在较长刚制水管一端,在另一端用锤重击一下钢管,可听见三次声音,则(  )

A.最先听见的是水传播的声音,最后听见的是钢管传播的声音

B.最先听见的是钢管传播的声音,最后听见的是空气传播的声音

C.最先听见的是空气传播的声音,最后听见的是水传播的声音

D.最先听见的是水传播的声音,最后听见的是空气传播的声音

答案

声音在固体中的传播速度最大,在液体中次之,在气体中最慢;

在敲击钢管时,声音既通过钢管传播,又通过水和空气传播,又因其在不同介质中的传播速度是不同的,所以先听到由铁管传过来的声音,其次听到由水传过来的声音,再听到由空气传过来的声音,共三次响声;

故选B.

综合
阅读理解

Answer the following questions by using the information taken from a dictionary page.(You may read the questions first.)

jaguar: n.a type of large, yellow-colored cat with black markings found in the southwestern region of the U.S.and in Central and South America.

jargon: 1.n.an unknown language that seems strange or impossible to understand.2.n.a language made up of two or more other languages: His jargon was a mixture of French and English- 3.n. the special vocabulary of a field or profession: Her report on computers was filled with jargon.4.n.speech that doesn't make sense.

jaunt: 1.n.a trip taken for fun.2.v.to go on a brief pleasant trip: We jaunted to the country last

Saturday.javelin: 1.n.a spear most commonly used as weapon or in hunting.2.n.the contest in which a javelin is thrown.3.n.a lightweight metal or wooden spear that is thrown in track-and-field contests.4, v.to strike, as with ajavelin.

jazz: 1.n.a type of music that originated in New Orleans and is characterized by rhythmic eats.2.n.popular dance music influenced by jazz..3.n.slang empty talk.4.ad.of or like jazz: a jazz band, jazz records.

Jennet; n.a small Spanish horse.

小题1:Which meaning of the word javelin is used in the sentence below?

At the competition, Jack drew his arm back and threw the javelin 50 yards.

A.Definition 1

B.Definition 2

C.Definition 3

D.Definition 4小题2:Which meaning of the word jargon is used in the sentence below?

Doctors often speak in medical jargon.

A.Definition 1

B.Definition 2

C.Definition 3

D.Definition 4小题3:What does the word jazz mean in the following sentence?

Don t give me that jazz, for lam a practical person.

A.nonsense

B.a kind of dance

C.a type of music

D.rhythmic beats