27.—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

27.—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
27.—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

27.—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
D
since + 一般过去时,主句现在完成时
不明白的再问哟,请及时采纳,多谢!

since 加从句的用法，后面用过去时，所以选D，joined
希望对你有帮助哦~

D since +过去一个时间点