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
网友回答
A. that
B. which
C. whose time
(答案→)D. by which time
解析：
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。