题目
---Why didn't you try your best to get on the subway （地铁）?
---I tried to,but it started moving _______ I could get on it．（ ）
---I tried to,but it started moving _______ I could get on it．（ ）
A.
before
B.
while
C.
as soon as
D.
after
知识点：状语从句章节：句法 / 复合句