问题

We should often keep _____ touch with each other, because we are good friends. [ ]
A: on
B: to
C: in
D:up
B: to
C: in
D:up
正确答案是:
同类题型
Where did you go on vacation?–I ___________.
The accident took place ______ a cold February evening. [ ]
Having been in hospital for two months, _______he was going to catch up with his classmates.
Do you go to school _____ seven thirty?[ ]
Great changes ______ in the city and a lot of buildings ______.