To fasten the seat belt

• 系紧安全带

To fasten the seat belt的用法和样例：

例句

1. For your own safety,please fasten your seat belts.
   安全起见，请系紧安全带。
2. When taking the roller coaster, you should put on your belt and fasten it.
   坐过山车时，你要系紧安全带。