（任务型阅读）
阅读下面的短文，并根据短文后的要求答题（请注意问题后的字数要求）。
Safety in the highway is not totally out of hands. Here are four ways we can protect ourselves when we travel.
You are safer in a large car. People in small cars are injured more often and more severely than people traveling in large cars. Factories of small cars are strengthening their products’ safety, which helps. But the mix of large cars and small cars on the road is the main reason of the problem.
Being thrown into glass and metal car parts, or being thrown from the car, can really damage to you. That’s why safety belts should be worn. The safety belt’s main purpose is ___________if your car has a sudden crash with another vehicle or object, or if it rolls over. A belt can reduce the chance of fatal injury by 45% and the chance of serious injury by 50%.
Air bags are important. More than half of all new cars sold have air bags. Air bags provide protection in frontal（正面的）crashes—the type of crash that kills the most drivers—when they are also wearing safety belts. Most people are demanding air bags in the cars they buy. But the protection provided by air bags is limited in side or rear crashes; effective as they are, they can’t take the place of safety belts.
Drunk driving crashes are less likely to happen if you don’t drink. Drunk driving is the most serious problem. Many people have realized that drunk driving can lead to death and injury, prison time and other results. There are movements to strengthen penalties（处罚） for drinking and driving.
1. What is the main idea of the passage? （Please answer within 10 words.）

2. Which of the sentences in the passage can be replaced by the following one?
Although they are effective, you should still wear your safety belts while driving.

3. Please fill in the blank with proper words to make the sentence completed.（Please answer within 6 words.）

4. Please translate the underlined sentence into Chinese.

6. What other suggestions can you offer? Why?（Please answer within 30 words.）