问题补充:
However,the incident was the only sparkthe fire.
A. which set off
B. set off
C. that set off
D. setted off
答案:
A. which set off
B. set off
(答案→)C. that set off
D. setted off
解析:考查定语从句。本题定语从句的先行词是the only spark,因为先行词前面有only修饰,且是表示物的名词,后面使用关系代词that指代先行词在 句子做主语。句意:然而,这个小事情是引起火灾的唯一的原因。根据句意说明C项正确。