―HaveyouknownDr.Jacksonforalongtime?―Yes,sinceshe

来源：语文精选馆 2.36W

―Have you known Dr. Jackson for a long time?

―Yes, since she________ the Chinese Society.

joined s joined ed

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。

知识点：一般过去时及其被动式