问题 问答题 简答题

简述脱氢乙酸及钠盐类。

答案

参考答案:

脱氢乙酸及其钠盐均为白色或浅黄色结晶状粉末,对光和热稳定,在水溶液中降解为醋酸,对人体无毒。是一种广谱型防腐剂,对食品中的细菌、霉菌、酵母菌有着较强抑制作用。广泛用于肉类、鱼类、蔬菜、水果、饮料类、糕点类等的防腐保鲜。

阅读理解

Popular music in America is what every student likes. Students carry small radios with earphones and listen to music before class, after class, and at lunch. Students with cars buy large speakers and play the music loudly as they drive on the street.

Adult drivers listen to music on the car radio as they drive to work. They also listen to the news about sports, the weather, and the life of American people. Most of the radio programmes are music.

Pop or popular music singers make much money. They make a CD or tape which radio stations use in many places. Once the popular singer is heard all over the country, young people buy his or her tape. Some of the money from these tapes goes to the singer. Wherever the singer goes, all the young people want to meet him or her.   Now the singer has become a national star.

There are other kinds of music that are important to Americans. One is called folk (民间) music. It tells stories about the common life of Americans. Another is called western or country music. This was started by cowboys (牛仔) who would sing at night to the cows they were watching. Today, any music about country life and the love between a country boy and his girl is called western or country music.

小题1:Which of the following is talked in this passages?

A.pop music, folk music

B.popular, folk and country music

C.pop music and western music

D.folk, pop and classical music小题2:When pop singers _________ , they will become national stars.

A.make much money

B.make a CD or tape

C.are loved by all the young people

D.are wanted to sing on the radio小题3:From the passage we know that country music is about the ________.

A.common life of Americans

B.country life and love stories

C.life of cowboys

D.school life in America小题4:What would be the best title (标题) for this passage?

A.American Music  

B.Popular Music

C.History of Music  

D.Western Music

单项选择题