If he isn't coming tonight, he might ... next week. You must be more polite ... the customers

1. If he isn't coming tonight, he might___next week.
A. To come
B.coming
C. Came
D. Come
2. You must be more polite____the customers.
A. Of
B. To
C. With
D. At
3. If you want to attend the course, yyou____pass the examination.
A. Have to
B. Has to
C. Had to
D. Could
4. We think that with our solidarity we can____this difficulty.
A. Overdo
B. Over go
C. Overtake
D. Overcome
TIỆN THỂ CHO MÌNH HỎI KHI NÀO DÙNG SINCE VÀ FOR
VÀ KHI NÀO DÙNG ON VỚI AT VÀ IN
CẢM ƠN NHA