drop by 和drop at 有什么区别?I dropped by my friend's house yesterday.可不可以用dropped at

没有dropped at这个词组

drop by vt. 非正式访问(顺便来访)
Drop by any time you are in town.
来城里的话就到我这儿来玩。
drop at,好像没有这个词组

drop by 随便访问
drop at 是经济词汇,意思是：(某日起)拒保
句子意思是：我昨天去了我朋友家.
dropped by不能换成dropped at