22. The open policy _______ the
development of the economy of China.
A. contribute to
B. contribute for C.
contributes to D. contributes for
23__________
your coat at once, and you will keep yourself warm.
A. Wear
B. Wearing C. Put
on
D. Putting on
24--- I wonder
why Mr. Green worried today.
--- I’m not sure, but he ______________ a small accident driving
here.
A. must have
had B. might have had C. might have D. could have