The 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
网友回答
A. though
B. never
C. hardly
(答案→)D. not only
解析：句意，这个男孩说不仅他解决不了这个问题，而且他的老师也不知道怎么做。not only…but（also）句型中，not only放在句首，前句部分倒装。