◎ 题干
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
◎ 答案
查看答案
◎ 解析
查看解析
◎ 知识点
    根据n多题专家分析,试题“He was busy writing a story, only ______ once in a while to smoke a cigarette.[ ]A. to stopB. stopping C. to have stopped D. having stopped…”主要考查了你对  【现在分词】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。