用现在时、过去时、将来时、现在完成时、各造一个被动语态

现在时，Stamps are used for sending letters.
过去时My homework was finished by me last night.
将来时The meeting will be held next monday.
现在完成时 Many books on science have been bought since I went to college.

1.一般现在时：History is made by the people.(历史是人民创造的)
2.一般过去时：These new cars were made in Tianjin in 2003(这些新车是2003年在天津生产的)
3.一般将来时：Many believe that one day the earth will be dostoryed if people do not lern to live in peace.(许多人相信，如果人类不能学会和平共处，地球总有一天要被毁掉).
4.现在完成时：He has been sent to work in Shanghai.(他已经被派往上海工作了)
5.过去完成时：A new hotel had been built when i got there.(我到达那儿时，新旅馆已经建好了)
6.将来完成时：Many new stadiums and gyms will have been built in Beijing by 2008(到2008年时，许多新的体育馆将在北京建成)

你没有说清楚是不是要一般时的还是别的，所以我全部写上了，你自己看吧。

My homework is done by me every evening.
My homework was done by me yesterday evening.
My homework will be done by me tomorrow evening.
My homework has been done by me.