问题

He was busy writing a story, only once in a while to smoke a cigarette.[ ]

A: to stop
B: stopping
C: to have stopped
D: having stopped

正确答案是：

同类题型

he increase of the people’s income, there is agrowing ______ for Chinese students to go abroad for further education.

Her mother does notof her going to study in the United States alone.[ ]

Just because they make more money than I do, _____ they seem to look down on me

It’s easy me English. I like it.

Are you going to take part in the speech competition—________. It’s too good a chance to miss.