Question

Turn on the radio. A program will come out from a broadcasting station miles and miles away. We know that sounds and music themselves couldn’t travel that distance through space .There must be something that brings the program from the station. But what is this silent carrier ( 載體) ?

This is known as radio waves. However, we can’t see them or even hear them. In fact, nobody knows exactly what they are. Nevertheless( 然而) ，we know that they are made by electricity .

At the broadcasting station, people talk, sing, play musical instruments or make many other sounds. These sounds are changed into electricity. Then from the broadcasting aerial (天線)of a tall tower , electricity sends out radio waves which travel in all directions .And some of them reach your radio aerial. What happens next is a magical thing. The radio waves start an electric current ( 電流) in your aerial like the one that was first made in the broadcasting station . Finally, the loudspeaker in your radio set changes the electricity into sound .Therefore, you hear the program.

根據(jù)材料內(nèi)容選擇最佳答案，將其標(biāo)號填入題前括號內(nèi)。

1.When you turn on the radio _________________.

A. you can see a program

B. you can hear a program

C. a picture will appear

D. you can feel the electric current.

2.The silent carrier that brings the program to you is called ____________.

A. radio set B. sound waves

C. radio waves D. radio current

3.Electricity sends out radios waves from _________________.

A. the broadcasting aerial of a tall tower.

B. you radio set

C. all directions

D. a broadcasting station

4.The electricity is changed into sound by _______________.

A. the radio waves B. the aerial

C. the radio program D. the loudspeaker

5.You may find this passage in a ______________.

A. guidebook

B. science magazine

C. fashion newspaper

D. fictional novel

 

Answer 1

1.B

2.C

3.A

4.D

5.B

【解析】

試題分析：打開收音機(jī)，節(jié)目會從幾公里外的廣播站傳來。傳播節(jié)目的載體是無線電波。在廣播站人們的聲音轉(zhuǎn)換成電流，通過高塔的天線傳送無線電波，最后收音機(jī)里的揚(yáng)聲器將電流轉(zhuǎn)換為聲音。

1.細(xì)節(jié)理解題。根據(jù)第一段第一、二句可知，打開收音機(jī)，節(jié)目會從幾公里外的廣播站傳來。故選B。

2.細(xì)節(jié)理解題。根據(jù)第一段最后一句和第二段第一句可以得知，傳播節(jié)目的載體是無線電波。故選C。

3.細(xì)節(jié)理解題。根據(jù)文章第三段第三句可知，電流通過高塔的天線傳送無線電波。故選A。

4.細(xì)節(jié)理解題。通過最后一段倒數(shù)第二句可以得知，最后收音機(jī)里的揚(yáng)聲器將電流轉(zhuǎn)換為聲音。故選D.

5.主旨推斷題。這是一篇科技文章，所以可以在科技雜志看到。故選B。

考點：科技類閱讀。