题目内容：

The fourth round of heavy smog to hit Beijing in four weeks has sent more people to the hospital with respiratory（呼吸的） illnesses and led to calls for laws to control the pollution.

Pan Shiyi, a celebrity real estate developer said he is planning to propose (提案) a Clean Air Act to the local government. As a representative to the Beijing Municipal People's Congress, he started an online survey at 9:20 a.m. Within three hours, more than 25,000 web users, or 99 percent of total respondents（应答者）, welcomed his proposal on Sina Weibo, China's Twitter.

They have good reasons to stand alongside Pan. The latest round of haze（雾霾）reduced visibility to under 500 meters in many parts of the city. The smog has also led to a great increase in respiratory illnesses, particularly among children and the elderly. Anxious parents and doctors almost all blame the smoggy air for the illnesses. Though most schoolchildren are home for the winter holidays, the bad air can easily move indoors. Besides, ordinary medical masks fail to provide adequate protection, so some people have turned to gas masks and respirators（呼吸器）.

The causes of the scary smog are rather mysterious, though experts blame excessive emissions and the mountains around Beijing that trap pollution in winter, unless there is adequate wind to clear it away. Some critics have pointed fingers at China’s top two oil firms, China National Petroleum Corp and China Petrochemical Corporation, saying the companies’ outdated production technologies produce large quantities of substandard, high-polluting gas fuel.

Meanwhile, concerned Beijingers have moved their brainstorming sessions to cyberspace. If Pan’s proposal for a Clean Air Act is adopted, netizens say the new law should include items providing for “car-free days” in times of smog, higher standards for vehicle fuel, stricter restrictions on industrial and exhaust gas emissions, and more effective protection for the public.

Beijing is not the only city that has ever lost the blue sky. Five days of thick fog caused thousands of deaths in Britain in December 1952, urging the government to pass the first Clean Air Act in 1956, which introduced smokeless zones and cleaner fuels to reduce pollution. That may provide some experience for Beijing to refer to.

1.What can we learn from the passage?

A．People are clear about the causes of the smoggy weather.

B．Children staying indoors will not get respiratory illnesses.

C．Smog is worse for people with lower resistance to diseases.

D．Masks can give people protection against the smoggy weather.

2.Britain is mentioned in the last paragraph to ______.

A．suggest Beijing should learn from other countries

B．let people know many places have this problem

C．tell people the situation in Britain is worse

D．call on the government to pass Britain’s Clean Air Act

3.What’s the best title for this passage？

A．The Use of Gas masks and Respirators

B．Beijingers Call for Clean Air Act

C．Effective Protection for Blue Sky

D．The Mysterious Causes of the Scary Smog