2. 职称英语
  3. In the past 50 years, there ______ a great increase in the amount of research on

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

游客2025-05-09  23
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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