Only after Helen moved to Australia how important she was to me .A. I had realizedB. had

问题补充：

Only after Helen moved to Australia how important she was to me .

A. I had realized

B. had I realized

C. I did realize

D. did I realize

答案：

A. I had realized

B. had I realized

C. I did realize

(答案→)D. did I realize

解析：考查倒装，因为only位于句首，所以用倒装，所以选D