It'shardtobelieve

問題詳情：

It's hard to believe ________ such a difficult maths problem without the help of the teacher.

A．what you will manage to work out

B．how did you you manage to work out

C．how you managed to work out

D．why did you manage to work out

【回答】

C

知識點：賓語從句

題型：選擇題