根据要求完成相关任务。

      在搭乘公共汽车和火车时，我们不但要遵守安全规则，还要注意礼让，才能拥有愉快的旅行。以下是搭乘公共交通工具时我们要遵守的一些安全规则及行为准则，用“R”  “C”。  

( )1. We should give our seats to an old person or a sick person. 

(     )2. Do not talk to the driver when the bus is moving. 

(     )3. Do not eat or smoke on the bus or train. 

(     )4. We should wait for people to get out of the elevator (电梯) before we go in.

(     )5. Do not open the door of the bus or train by yourself.

(     )6. We should queue up (排队) at the bus stop or taxi stand.