I will hold your note until Christmas Day,________ you certainly will have received your allowance
问题描述：
I will hold your note until Christmas Day,________ you certainly will have received your allowance
A.by that time
B.at that time
C.by which time
D.at which time
答
C 非限制定语从句
which time 指代前面的 Christmas day
从句将来完成时 用by which time