一、什么时候用被动语态
1.don't know who is doing the action.
2.don't care who dose the action.
3.委婉的说法
二、被动语态的构成
1.subject + is / was / will be / have or has been +pp +其他
① my hair is cut.
my hair is cut by Tonny.(如果想强调人的话可以用by xx)
② The cookies were eaten.
③ You article was read but I think you still need to rewrite it again.(比较委婉的说法)
I read you article but I think you still need to rewrite it again.(直接的书法，容易伤人)
