We college students traveled from door to door, dropping _______ on families and listened to their problems.
A. in B. from C. by D. away
我选的是C，答案是A，为什么呢。
另一道：
3. ----- You forgot to wear your dark glasses when you went fishing.
----- Good heavens! __________.
A. So did I B. I did so C. So I did D. I also did
