For the safety, everyone _________ obey the traffic rules when he is driving or walking.

No free plastic bag in the supermarket helps to _____ white pollution.

Dad, why must I stop ______ computer games?—For your health, my boy.

In the United States, ______ a car most people feel that they are poor. — Yes. Cars are the most important part of life to them. [ ]

Could you tell methis summer holiday?-Tibet.