I __ to Las Vegas by the time you__back next week

Question

I __ to Las Vegas by the time you__back next week A,am going ; come B.will have gone;come C.am going;will come D,shall go;will come

Answer 1

B追问

为什么？？？

追答

by the time 连接的时间状语从句，主将从现，从句一般现在，you第二人称主语，动词用原形就行了；主将，by又要求完成，那就结合成“将来完成时态”了......