Onlyafterhehadspentseveralnightsworkingonthemathsproble...

問題詳情：

Only after he had spent several nights working on the maths problem ________to  wonder whether the problem was wrongly set.

A．he began  B．that he began

C．he did begin  D．did he begin

【回答】

D　考查倒裝句。當“only＋狀語”放在句首時，主句要用部分倒裝結構。

知識點：倒裝與省略

題型：選擇題