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回答时间:2024-05-16 14:37
be+done只是一个公式,具体用他们的那种形式还得看具体的时态。例如:
My mother buys a bike.
A bike is bought by my mother.这里的be 咱们就是用的它的其中一个形式;再举个例子:
Teenagers should wear school uniforms.
School uniforms should be worn by teenagers.这里就是用的be ,原因是should是情态动词,后面就要用动词的原型,am,is ,are ,was were的原型就是be.明白了吗?
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