I'll ring you up ____ I arrive in Shanghai A befor B though C as _英语解答

I'll ring you up ____ I arrive in Shanghai A befor B though C as soon as D but
请高手们给出解答的理由

人气：405 ℃　时间：2019-10-23 06:36:51

解答

C as soon as
一.就.的意思.
A befor 在.之前
B though 虽然
D but但是