阅读理解。 All my friends at school smoked. My dad smoked, he didn't want me to smoke, but my friends kept saying I was stupid. They asked when I was going to grow up. So I started to smoke when I was sixteen and after a month I couldn't stop. But two years later I could feel what smoking was doing to me. I couldn't run far, and I coughed every morning. I got very ill and decided to stop. It wasn't easy, but now I've done it, and I feel better. Now I have money for other things. If you smoke, you are twice as likely to die from a heart attack. And the more you smoke, the earlier the heart attack is likely to be. For example, a 50-year-old person who smokes more than 20 cigarettes a day, is four times more likely to have heart disease than a non-smoker of the same age. What does smoking do to the heart? First of all, it makes the heart beat faster and increases the blood pressure. The cigarette smoke also reduces the amount of oxygen in the blood. Consequently, the heart has to work harder, with less oxygen. Finally, your arteries will narrow faster if you smoke. So if you want to reduce your chances of getting heart disease, the answer is easy, not to smoke. Don't copy your friends and other people who smoke. If you smoke, find out how to stop. Stopping isn't easy, but you'll be healthier, and… 根据短文内容，选择正确答案。 1. Who is more likely to have heart disease? A. A smoker. B. A non-smoker. C. A 50-year-old person. 2. What does the writer think of smoking? A. It is good for his health. B. Smoking is bad for him. C. It is neither good nor bad for his health. 3. What happens after the writer stopped smoking? A. He becomes rich. B. He has more friends. C. He becomes healthier and has money to do other things. 4. Which is TRUE according to the passage? A. The writer started smoking when he was twenty. B. Smoking makes the heart beat faster and increases the blood pressure. C. The writer thinks stopping smoking is easy. 5. What's the writer's purpose to write the passage? A. To persuade people not to smoke. B. To tell us his story at school. C. To tell us the harm of a heart attack.