Question

【題目】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

Answer 1

【答案】D

【解析】試題分析：考查時(shí)態(tài)。句意：在二戰(zhàn)以前，這種實(shí)驗(yàn)已經(jīng)在美國和歐洲進(jìn)行了無數(shù)次。experiments與conduct是動(dòng)賓關(guān)系，應(yīng)該用被動(dòng)，排除A、C；根據(jù)“before the Second World Wall”可知，應(yīng)該用過去完成時(shí)，故選D。