Not until he took off his sunglasses him.
A. I recognized
B. I did recognize
C. did I recognize
D. do I recognize
网友回答
A. I recognized
B. I did recognize
(答案→)C. did I recognize
D. do I recognize
解析：考查倒装结构。. Not until放在句首要部分倒装，根据前面动词时态为过去式，所以选C.
句意：直到他摘下眼镜我才认出了他。