-Have you known Dr.Jackson for a long time?-Yes,since she () the chinese society.A has joined B joined选择一项并说明不选另一项的理由

-Have you known Dr.Jackson for a long time?-Yes,since she () the chinese society.A has joined B joined选择一项并说明不选另一项的理由
-Have you known Dr.Jackson for a long time?
-Yes,since she () the chinese society.
A has joined
B joined
选择一项并说明不选另一项的理由

-Have you known Dr.Jackson for a long time?-Yes,since she () the chinese society.A has joined B joined选择一项并说明不选另一项的理由
选B~根据提问者的意思,我们可以确定,回答的这句话应该是表示一段时间的结构.join是个非延续性动词,只能用一般过去式,所以选B.如果想选A,应该改为has been in.

B
since从句中要用一般过去时态

since 后跟时间点，不能是延续性的
选B

B