无套被口感染梅毒几率:求助英语中，for,of,in,on,with和at的用法与区分！

求助英语中，for,of,in,on,with和at的用法与区分！ [急]英语选择题：Are you here ( ) business? A.for B.in C.on D.of 请告诉我in,at,for,of,on的用法 to on at in of for 怎么区别？~~~ for,to,at,on,in,of分别有什么作用？ Come On In For A Piece Of Question Come On In For A Piece Of Question 在线等选择填空Bad weather-----the time of year. A.in B. for. C. of D. on 在外贸中 in the terms of 和on receipt of 是马上意思啊？ there must always be someone on duty who is capable of standing in for the person who is anyway.