It's the first time ,for the first time ,the first time ,at

It's the first time ,for the first time ,the first time ,at for the first time. At the first time、The first time、For the first time 、On the the first time,for the first time,at the first time 怎么区别?（我不 the first time 和at the first time和for the first time的区别 for the first time和the first time和at the first time有什么区别? the first time/at the first time/ for the first time 求in the first time和at the first time 、for the first time的区别~ on the first time ;in the first time; at the first time; for 用for.the.first.time和at.first 和it.was.the.first.time和the.firs the first,for the first time,first time,by the first time的区别 for the first time,first time,the first time和by the first ti