in sb's vacation 和on sb's vacation的区别

in sb's vacation 和on sb's vacation的区别 一个英语方面的问题（简单）for sb's birthday 和 on sb's birthday for vacation 和 on vacation的区别 in vacation和on vacation的差别 on vacation 和in vacation和for vacation的区别:-D in the vacation ；go on vacation ；on vacation 区别? for vacation和on vacationMy parents are in Beijing (for) vacation.为什么用for不用on in vacation,on vacation的区别 应该用in vacation还是on vacation go for one's vacation /on vacation/ take a vacation 急用Put sb on和Put sb in的区别! on vacation 和 for vacation的区别 on vacation和for vacation哪个对 on sb's success, follow on sb.s heels;in the wake sb's+sb's和sb+sb's的区别 go on vacation 和go on a vacation 的区别? 请问是in summer vacation还是on summer vacation? 是in vacation,还是on vacation,还是atvacation?