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

下列句子中，没有语病的一句是（）

When the book，Twilight，was first ________，it was immediately well received by readers.

exercise you take , you’ll be.

The old man had three sons, all of ____ died during World War Ⅱ.

How dangerous it was!- – Yes, but for the passer – by’ s quick action, the child _____．