－To keep safe everyone wear a seat belt(安全带) in a car.A. is suppose B. are supposed to C.

问题补充：

－To keep safe, everyone wear a seat belt(安全带) in a car.

A. is suppose B. are supposed to C. is supposed to D are supposed

答案：

解析：此题考查固定短语be supposed to do sth表示应该做某事，everyone表示个体做主语时谓语动词要用单数形式。