被动语态,一般现在时,More than eight million tourists visit Paris every year.,Paris is visited by more than eight million tourists every year.,一般现在时 动词visit,be + 过去分词,一般过去时,Leonardo da Vinci painted the Mona Lisa.,The Mona Lisa was painted by Leonardo da Vinci.,一般过去时 paint,be + 过去分词,The slaves built the Great Wall long long time ago.,The Great Wall was built by the slaves long long time ago.,一般过去时 build,be + 过去分词,现在进行时,am is are + V-ing,The girls are singing the song now.,The song is being sung by the girls now.,现在进行时 sing,be + 过去分词,过去进行时,The girls were singing the song when I got there.,Was were + v-ing,The song was being sung by the girls when I got there.,过去进行时 sing,be + 过去分词,The three Gorges Dam harnesses the power of the Yangtze River. The power of the Yangtze River is harnessed by the three Gorges Dan.The flood water submerged many historical sites. Many historical sites was submerged by the flood water.The power station generates three quarters electricity. Three quarters electricity is generated by the power station.,The experts are discussing this question.,The students were cleaning the room when I arrived.,This question is being discussed by the experts.,The room was being cleaned by the students when I arrived.,