问题
Not only China but also other countries _____trying to develop their own economy.[ ]
A: is
B: are
C: has
D: be
B: are
C: has
D: be
正确答案是：
同类题型
John kept looking at the pretty girl, wondering whether he_________ her somewhere
The old couple have been married for 40 years and never once _______ with each other.
not be a great suggestion But before _______is put forward, we’ll make do with it