Someone called me up in the middle of the night,but they hung up__could answer the phone

问题描述:

Someone called me up in the middle of the night,but they hung up__could answer the phone
A.as
B.since
C.until
D.before
顺便问一下是几年级的题目

D
是不是--后面少写了I?
半夜有人给我打电话,不过在我答电话前他就挂了.