题目内容：

While students in Yinchuan are quite used to clear skies, Beijing teenagers are not so lucky. As another warm winter approaches, the city can expect the normal clouds of smoke caused by air pollution.

But things may start to improve soon. The government is co-operating with a US-based environmental protection agency to update existing buses and trucks with clean fuel technology. The new technology could reduce air pollutants in existing diesel engines(柴油机)by 40 percent. The programme will begin by testing buses in Beijing to see if the technology can be applied to them.

“We encourage the development of public transports. But at the same time we need to reduce pollution from them, ”said an official.

Efforts are being made to improve the capital’s environment with tighter controls on emissions(排放). Some heavily polluting factories and construction sites, such as those owned by the steel giant Shougang Group, have been asked to cut production in November and December or be closed.

Beijing was the third polluted city in the world at the end of last century, according to the UN. But thanks to recent measures, the capital has made some progress. Last year 224 clear days were rated as having good air quality. In 1998 the air quality index(指数)gave just 100 days as good.

“I am glad to see an improvement, ”said a senior 1 boy living in the northwest of Beijing. “Compared to other places, the air quality of Beijing is still worrying though. I hate pollution. Once I was riding my bike in the morning when I almost had a traffic accident because I couldn’t see a car only metres away from me in fog. ”

In early October, the skies were covered by such a thick fog that a display show by the visiting French Air Force was called off.

Rapid development, industry, traffic fumes and sandstorms from the desert all contribute to the city’s bad air.

1.The passage is mainly about   .

A. a programme aiming at improving Beijing’s air quality

B. progress made in Beijing’s air quality

C. Beijing’s air pollution

D. the differences between Yinchuan and Beijing

2.Which of the following is NOT the measure taken or to be taken to improve Beijing’s air quality?

A. Clean fuel technology will be used in public transports.

B. Some factories have been asked to cut production.

C. Some construction sites have been told to be closed.

D. A display show of airplanes has been called off.

3.We can infer from the passage that, with the aim of being an ecological city,    .

A. far more still needs to be done

B. nothing else needs to be done

C. all traffic has to be closed

D. the development of the city has to be slowed down

4.Which of the following is NOT correct according to the passage?

A. Beijing’s air quality is getting worse and worse.

B. Rapid development, industry, traffic fumes and sandstorms are all the causes of bad air quality.

C. People see clouds of smoke in the sky in the winter of Beijing.

D. The government is making efforts to stop air pollution.