问题
选择题
In the office I never seem to have time until after 5:30 pm, _____ many people have gone home.
A．that
B．which
C．whose time
D．by which time
答案
答案：D
D。by which time 引出的是一个非限制性定语从句，其中 by which time 相当于 and by that time。