New medicines and instruments every day to extend life.A. developB. are being developedC

发布时间：2020-08-14 23:20:41

New medicines and instruments      every day to extend life.
A. develop
B. are being developed
C. are developing
D. have developed

网友回答

A. develop
(答案→)B. are being developed
C. are developing
D. have developed
解析：因为“新的药物和器械”与“开发”之间为被动关系，故用被动语态。
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