He was busy writing the exam paper , only ___once in a while to check the time.

题型：不详难度：来源：

A．to stop

B．stopping

C．to have stopped

D．having stopped

答案

解析

考查分词做状语。He与stop构成主动关系，使用现在分词的形式。句意：他忙于做试卷，只是偶尔停下来核对一下时间。

举一反三

The news reporters hurried to the airport, only _________ the film stars had left.
A to tell B to be told C telling D told

题型：不详难度：| 查看答案

Nature has provided Shangri-la with endless natural treasures, _________ the land a happy home for the local people.
A made B having made C making D to make

题型：不详难度：| 查看答案

_________ that government can lead them out of the financial crisis, people are optimistic about the future of the country.
A Convincing B Convinced C To convince D Having convinced

题型：不详难度：| 查看答案

The next thing he saw was smoke ________ from behind the house.
A rose B to rise C rising D risen

题型：不详难度：| 查看答案

I had great difficulty the suitable food on the menu in that restaurant.

A．find

B．found

C．to find

D．finding

题型：不详难度：| 查看答案