主語+be+過去分詞+by+人物.
be詞根據(jù)句子不同時態(tài)而變化.
(1)The letter is written by him.
(2)The floor was swept by her.
(3)This hospital was set up in 1975.
(4)He was saved at last.
(5)The work has been done.
(6) The railway was being built this time last year.
(7) A new railway is being built in this city.
(8) He told us that the new railway would be built the next year.
(9)Knives are used for cutting things.
一般現(xiàn)在時：am／is／are＋V-ed
一般過去時：was／were＋V-ed
一般將來時：will／shall be＋V-ed
現(xiàn)在進(jìn)行時：am／is／are being＋V-ed
過去進(jìn)行時：was / were being + V-ed
現(xiàn)在完成時：have／has been＋V-ed
過去完成時：had been＋V-ed
將來完成時：shall / will have been + V-ed
過去將來完成時：would / should have been + V-ed