Question

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

Answer 1

答案B
句意：他忙着编故事，偶尔停下来吸只烟。此题容易错选A。但only to do 表结果，人、而根据题意可知，此处表伴随且stop 几乎与was busy 同时发生，故用B，而having stopped 表示此动作限于谓语动词发生，与题意明显不符。