We must know what we should do and what
问题:
We must know what we should do and what we should avoid _______ a good impression on others in public places.
A.to leave
B.leaving
C.to have left
D.leave
We must know what we should do and what we should avoid _______ a good impression on others in public places.
A.to leave
B.leaving
C.to have left
D.leave