Wang Bing's father began smoking when he was a freshman ( )in college. His friend passed him his first cigarette. He has now been smoking for more than 30 years. It's a classic example of how young people are introduced to cigarettes, except that nowadays smokers develop their habit at an even younger age. It has become a major concern  in China that many teenagers begin to smoke. A survey showed that 22.5% of the middle school students questioned had tried smoking and 15.8% of them smoked regularly. For many teenagers, smoking is a symbol of being an adult, independence, maturity  and attractiveness because the images who they love best often smoke on screen. The social environment also plays an important role in attracting teenagers to smoking. They are used to seeing their elders, especially male family members, smoking at home. Many of them _ adult behavior and become new smokers. To increase the price of cigarettes is an effective way to reduce the number of young smokers, as teenagers have limited money to spend on them. Another way is to educate the teenagers to voluntarily refuse cigarettes. A survey shows that 92.5% of the students know smoking will be bad for their health. If we persuade them in a proper way, most of them may give up smoking. All in all, the society, the government, the school and the family should join together to take the responsibility for an anti-smoking   campaign aimed at teenagers, _ What's the main idea of this passage?
The teenagers think smoking is a symbol of being an adult and independence. The social environment encourages the teenagers to smoke. The teenagers should be educated to refuse to smoke. The teenage smoking has become a serious problem in China.