—Have you known Dr. Jackson for a long time?—Yes since she the Chinese Society.A. has joi

问题补充：

—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：

A. has joined

B. joins

C. had joined

(答案→)D. joined

解析：该句完整的句式是：I have known Dr. Jackson since she joined the Chinese Society. since后跟的时间状语从句要用一般过去时，表示自从过去某个时间发生的动作到现在以来有多长时间了。