根据所给汉语，写出句中所缺的词语。

1.You could                  (自愿服务) in a hospital.

2.I'd like to help                    (无家可归) people.

3.We often visit                   (小学的，初级的) schools and help the teachers.

4.A girl won a million                 (美元) in the lottery.

5.Before you borrow something from a friend, you'd better ask his or her                 (许可).

当顶灯开关处于“DOOR”位置时（）

A.顶灯常亮

B.顶灯常灭

C.开门是顶灯亮

D.以上均不对