题目内容：

SHANGHAI——Health researchers in Shanghai are calling for more protection for young children as the latest research shows about half of the children are suffering（受折磨）from secondhand smoke.

About 45% of children suffer passive（被动的）smoking in families, 50% in public places, and almost 6% on public transportation, shows a research reported by the Shanghai Children's Medical Center (SCMC)on Tuesday.

"Not only adults but also children and newborn babies are at risk for the bad effects of passive smoking," said Tang Jingyan, a doctor. Research has shown that children who are living in a secondhand smoke situation will suffer from more colds, coughs and sore throats, and they are more likely to suffer from pneumonia(肺炎）and will have a higher risk of developing cancer. Doctors even suggested that children suffering passive smoking are more likely to have behavioral problems and may not develop mentally(智力上) as quickly as other children.

Other research by the SCMC has found that more than 80% of child patients in the center live in a smoke-filled household, where one or both parents smoke. "Though doctors have stressed the harm of passive smoking over and over, it is still hard to reach a totally smoke-free home," said a doctor named Zhang Yiwen. Parents often want to smoke even though the have learned the harmful effects of secondhand smoke.

China has 540 million people suffering from passive smoke,180 million of the younger than 15, the age of smokers is also getting lower, "earlier reports said. "There are more young smokers than before. You can see young people wearing a school uniform(校服）and carrying a schoolbag light a cigarette(香烟）on the street. Some of them are even girl students," said Jing Xingming, a professor. "Children like to copy adults, especially their parents. If parents often smoke at home, it is very likely children will develop a smoking habit which can cause a bad circle," Jin said.

Reports from the Ministry of Health said China has about 350 million smokers, of whom 15 million are underage smokers. Also, around 40 million of the country's 130 million children aged between 13 and 18 had tried smoking, and 15 million had become addicted to(上瘾) smoking.

1.What is Paragraph 3 mainly about?

A.The bad effects of passive smoking. B.The influences of adults to children.

C.The bad living situations of children. D.The attitude towards children smoking.

2.What can we learn from the passage?

A.About 45% of children suffer passive smoking in public places.

B.About 40 million children aged between 13 to 18 tried smoking.

C.About 350 million children are heavy smokers in China.

D.About 80% of the children in the SCMC smoke heavily.

3.What is the writer's main purpose in writing this passage?

A.To question about the behaviors of the children smokers.

B.To show the reasons why children like learning smoking.

C.To call on people to protect children from secondhand smoke.

D.To encourage children to give up smoking as soon as possible.