问题

Sales of CDs have greatly increased since the early 1990s, when people _______ to enjoy the advantages of this new technology

A:begin
B:began
C:have begun
D:had begun

正确答案是：

同类题型

The work ____ be finished in such a short time .

I think Miss Lin must be in the library.She said she would go there.—No, she __________be there. I have justbeen there.

Have yousome new ideas? -Yeah.I’ll tell you later.

What about going out for ______ walk this weekend—-Good idea.I love getting close to _____nature.

______, I believe, and you will find Tom is very outgoing.