阅读下篇材料，从所给的A---F六个选项中，选出正确的选项填空，使短文通顺内容完整。（有一项多余）
Cars have lots of fun, 小题1:______We have to be careful when we drive them or ride in them.It’s always a good idea to put on your seat belt(安全带)when you are in a car.Why?Think about this example小题2:_____If the skateboard hits a stone,it will stop,but the egg won’t.It will fly through the air,hit the ground and break.Now,think what would happen if you tie the egg to the skateboard.When the skateboard hits a stone,the egg won’t go flying;it will stay safely on the skateboard.This example shows小题3:_____Volvo,a famous Swedish carmaker,was the first to use the seat belt in 1849.Air bags(安全气囊)are also very important for car safety,小题4:____If the car is going really fast and runs into(撞上)something,seat belts could even hurt the people who wear them.
Most new cars have air bags in front of and next to the seats.小题5:____its air bags will come out quickly-----in less than one second-------to keep the people inside safe.

A. you put an egg on a skateboard and give it a push. B. because sometimes a seat belt isn’t enough. C. When a car hits something D. They are very useful E. why it is so important to wear a seat belt when you are in a car. F. but they could also be dangerous.