问题补充：
So amused that I couldn’t help laughing when I saw the children dressed up as Santa Clauses on Christmas Day.
A. did I feel
B. had I felt
C. was I felt
D. I felt
答案：
(答案→)A. did I feel
B. had I felt
C. was I felt
D. I felt
解析：
试题分析:考查倒装句。当so…that句型中的so+ 形容词部分位于句首时，后面出现部分倒装语序，所以排除D选项。因为felt 和 saw动作几乎同时发生，所以应该用一般过去时态，此外动词feel应借助于助动词构成部分倒装，所以A选项正确。句意：当我看到孩子们在圣诞节打扮成圣诞老人的样子时觉得如此好笑以至于抑制不住地大声笑起来。
