Our English teacher _____ in our school since he _______ to China.

问题描述:

Our English teacher _____ in our school since he _______ to China.
A:has taught,come B:taught ,…come
C:has taught,has come D:teaches,has…come

没答案啊,应该是has taught,came
意思是自从我们英语老师来到中国,一直在我们学校教书.
since表示自从的意思,引导时间状语从句.从过去某一点时间到现在,所以since从句中用一般过去时,主句用现在完成时