All kinds of techniques and medicines ______ to extend human beings’ live in recent years.

2023-05-26

A.have been developed
B.are being developed
C.were developed
D.develop

参考答案:A

本题考察动词的时态和语态,题目意为“近年来,各种各样延长人类生命的技术和药物都被开发出来了。”主语是“技术和药物”,因此要使用被动语态,时间状语是in recent years,时态用现在完成时。

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