The headmaster asked me to_____ him at his office.

The headmaster asked me to_____ him at his office.
A、drop in
B、call in
C、drop in on
D、call on in
【正确答案】:C
【题目解析】:drop in 落进;call in 召集;drop in on 顺道拜访;call on in 错误搭配,call in on 才是顺道拜访的意思;句意:校长让我到他的办公室去拜访他。因此C符合题意