---You must come back every day .---Yes,I will.请问这里为什么用will

---You must come back every day .---Yes,I will.请问这里为什么用will You must come back every month.Yes,I ( ).选 will,must,should 需要解答（英语）1.-You must come back every month.-Yes I ___.A.will A:You must come back every month B:Yes,I___ (A)will (B)must为 when will you come back 为什么用back ---------will you come back? I WILL COME BACK I will come back for you! You promised I will come back. ___for New York?Yes.And i will come back next week.空格处为什么是R I will tell you when he will come back I hope you will happy every day