问题
选择题
—Have you known Dr. Jackson for a long time?
—Yes, since she _________ the Chinese Society.
A．has joined
B．joins
C．had joined
D．joined
答案
答案：D
.
D。since she join the Chinese Society为I have known Dr. Jackson since she join the Chinese Society之省略。连词since所搭配的时态通常是：主句用现在完成时，从句用一般过去时。
单端固定桥（无
）戴用2年余，近一时期自觉基牙松动，冷热疼痛不适。查：