Only then how much damage had been caused.
A. she realized
B. She had realized
C. had she realized
D. did she realize
网友回答
A. she realized
B. She had realized
C. had she realized
(答案→)D. did she realize
解析：only + 状语 / 状语从句位于句首时，句子/ 主句要用部分倒装。将谓语的一部分(即情态动词、系动词或助动词)提到主语前的称为部分倒装。如句中没有情态动词、助动词或系动词，谓语只是一个实义动词，要在主语前加助动词do，does或did，主语后的实义动词用原形。