Icaughtseveralfishafterfourhours,andonlythen

問題詳情：

 I caught several fish after four hours, and only then _____ that the secret of success was patience.

      A. I realized        B. I had realized       C. did I realize    D. had I realized

【回答】

C

知識點：倒裝與省略

題型：選擇題