问题 选择题

Experiments of this kind   in both the U.S.and Europe well before the Second World War.

A.have conducted

B.have been conducted

C.had conducted

D.had been conducted

答案

答案:D

本题考查时态。根据句中时间状语before the Second World War可知用过去完成时,由于experiments与conduct为被动,故选D。

选择题
判断题