I know Mr. Shuili; we to each other at an English lecture.A. are introducedB. are been in

问题补充：

I know Mr. Shuili; we to each other at an English lecture.

A. are introduced

B. are been introduced

C. were introduced

D. had been introduced

答案：

A. are introduced

B. are been introduced

(答案→)C. were introduced

D. had been introduced

解析：考查时态。根据句意：我认识Shuili先生，我们在一场英语讲座上已经被介绍过了。故用一般过去时，选C。