题目内容
New medicines and instruments ______ every day to extend life.
A. develop B. are being developed
C. are developing D. have developed
B
从语境上看,develop 不仅要用被动语态,而且要用进行时态。
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题目内容
New medicines and instruments ______ every day to extend life.
A. develop B. are being developed
C. are developing D. have developed
B
从语境上看,develop 不仅要用被动语态,而且要用进行时态。