Question

----You seem to have known Dr Smith for a long time.
---- That’s true. ______ he joined our club six years ago.

A．Since

B．Until

C．When

D．Before

Answer 1

A

介词辨析. A.自从……    B.直到，常和not一起连用；C.当……时候  D. 在……之前。根据题意，你好像认识史密斯博士好久了。——这是真的。自从他六年前加入我们俱乐部以来就认识。故选A。