問題詳情

36. With the help of high technology, more and more new substances ______ in the past years.
(A) discovered
(B) have discovered  
(C) had been discovered
(D) have been discovered

參考答案

答案:D
難度:適中0.5
統計:A(0),B(0),C(0),D(0),E(0)

用户評論

【用戶】步筱昕

【年級】高三下

【評論內容】由句中的时间状语in the past years可知,空格应填现在完成时;又因句子中的主语new substances与discover为被动关系,故选D项。