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：句意：就在那时她才意识到已经引起多么大的伤害。Only then放在句首句子应该用部分倒装，根据had been caused可知realize应该用过去式，故用D。