练习：
1.An English song will be sung by the children.
2.The meeting room shall be painted by us.
3.The work wiil not be finished by the workers on time.
4.The visitor will be shown to the library by the librarian.
5.The letter won’t be sent to the post office by him.
6.The right answers won’t be chosen by me.
7.Will the books be taken by them?
8.Shall an English song be sung by me?
9.Where will the birthday party be held by them?
10.When will the bike be mended by you?
二、
1.Was the window broken by him yesterday?
2.The books were taken away yesterday by someone.
3.A sports meeting will be held in September by us.
4.The babies were taken good care of by the nurse.
5.The glass was broken by the cat.
6.I was given a computer as my birthday present from mum.
A computer was given to me as my birthday present by mum.
p.s.
关于二6中的第一句我觉得用by怪怪的不顺口改成from了.学这些东西太久了忘了你们的规范了.另外,如果你们是刚学就没有问题；如果学了很多了有些句子里by sb.是可以去掉的.嗯以上.
