More than a dozen students in that school abroad to study medicine last year.A. sentB. w

问题补充：

More than a dozen students in that school abroad to study medicine last year.

A. sent

B. were sent 

C. had sent

D. had been sent

答案：

A. sent

(答案→)B. were sent 

C. had sent

D. had been sent

解析：be sent abroad 表示“被派往国外”。有明确的过去时间状语last year，所以用一般过去时的被动形式。