问题补充：
Nothing he did was helpful to solve this problem, ?
A. didn’t he
B. was it
C. wasn’t it
D. did he
答案：
A. didn’t he
(答案→)B. was it
C. wasn’t it
D. did he
解析：考查反意疑问句。句意“他所做的对解决问题毫无用处，不是吗？”nothing表示否定，故反意疑问部分用肯定，排除A、C；前面用的be动词was，故后面也用was，排除D。故选B。
