问题 单项选择题

大气污染是指大气中的污染物或由它转化成的二次污染物的浓度达到了有害程度的现象。造成大气污染的主要物质是(  )。

A.一氧化碳

B.二氧化碳

C.二氧化硫

D.氢氧化物

答案

参考答案:C

解析:大气污染物主要分为有害气体(二氧化硫、氮氧化物、一氧化碳、碳氢化物、光化学烟雾和卤族元素等)及颗粒物(粉尘和酸雾、气溶胶等)。其中二氧化硫是一种分布广、危害大的主要大气污染物。故答案选C。

阅读理解

Most shops in Britain open at 9:00 am, and close at 5:00 or 5:30 in the evening. Small shops usually close for an hour at lunchtime. On one or two days a week—usually Thursday and/or Friday—some large food shops stay open until about 8:00 pm for late night shopping.

Many shops are closed in the afternoon on one day a week. The day is usually Wednesday or Thursday and it is a different day in different towns.

Nearly all shops are closed on Sundays. Newspaper shops are open in the morning, and sell sweets and cigarettes as well. But not all the things can be sold on Sundays.

Usually it is not difficult for foreign visitors to find where to buy things. Most shops sell the things that you want to buy. One problem is stamps. In Britain you can only buy these at post offices. Many large food shops are self-service. When you go into one of these shops, you take a basket and you put the things you wish to buy into this. You pay for everything just before you leave. If anyone tries to take things from a shop without paying they are almost certain to be caught, because most shops have detectives.

When you are waiting to be served in a shop, it is important not try to be served before people who arrive before you. Many foreign people are surprised at the British way of queuing (排队).

1 Most shops in Britain stay open for about ______ a day.

A. eight hours    B. five hours    C. ten hours    D. six hours

2 According to the passage, which of the following statements is NOT true?

A. Some large food shops open for about 11 hours on Thursday or Friday.

B. Many shops are closed in the afternoon once a week on Tuesday.

C. Only a few things can be bought on Sundays.

D. It is not difficult for foreign visitors to buy things in Britain.

3 You can not buy ______ in shops.

A. cigarette    B. sweets    C. stamps    D. clothes

4 Which of the following statements is TRUE?

A. Most shops usually close for an hour at lunchtime.

B. Many large shops are self-service.

C. Most shops have detectives.

D. People do not have to queue to be served.

5 Which of the following statements can be the best title of this passage?

A. Shops in Britain

B. How to buy things in Britain?

C. The British Way of Queuing

D. How long are the British shops?

单项选择题