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：当“only+状语”置于句首时，其后句子要用倒装语序，如：Only then did he realize that he was wrong. 到那时他才意识到他错了。Only in this way are you able to do it well. 你只有用这种方法才能把它做好。