They boy said couldn’t he work out the problem but his teacher didn’t know how to do it.A

问题补充：

They boy said couldn’t he work out the problem but his teacher didn’t know how to do it.

A. though

B. never

C. hardly

D. not only

答案：

A. though

B. never

C. hardly

(答案→)D. not only

解析：not only…but（also）句型中，not only提前句子倒装。