In the past 50 years, there ______ a great increase in the amount of research on

游客2025-05-09  1

问题 In the past 50 years, there ______ a great increase in the amount of research on the human brain.

选项 A、was.., did
B、has been.., to be done
C、was.., doing
D、has, been.., done

答案 D

解析 根据in the past 50 years判断,需用现在完成时;过去分词短语和不定式都能做定语,但本句想表达的是已经做了的实验,因此应用过去分词表完成和被动,选项D正确。
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