问题
选择题
New medicines and instruments ______ every day to extend life.
A．develop
B．are being developed
C．are developing
D．have developed
答案
答案：B
从语境上看，develop 不仅要用被动语态，而且要用进行时态。
搜题请搜索小程序“爱下问搜题”
New medicines and instruments ______ every day to extend life.
A．develop
B．are being developed
C．are developing
D．have developed
答案：B
从语境上看，develop 不仅要用被动语态，而且要用进行时态。