`11` This factory wasn't built by the German during the Second World War 

`=>` Câu bị động thì Quá Khứ Đơn : S + was/were + Ved/V3 + ( by O )

`12` This house and these cars are going to be painted for Christmas Day by the Greens

`=>` Câu bị động thì TLG : S + is/am/are + going to + be + Ved/V3 + ( by O ) 

`13` The cats had been fed by Ann before she went to the cinema

`=>` Câu bị động thì QKHT : S + had + been + Ved/V3 + ( by O ) 

`14` The pollution problems have been discussed by the students since last week 

`=>` Câu bị động thì HTHT : S + has/have + been + Ved/V3 + ( by O ) 

`15` Has the most valuable paintings been stolen by the thieves in the national museum ? 

`=>` Câu bị động thì HTHT : Has/have + S + been + Ved/V3 + ( by O ) ? 

`@` Note : 

`+` Nếu chủ ngữ là somebody , they , someone,people thì không được dùng by + O 

`+` Trạng ngữ thời gian và nơi chốn thì đứng sau by + O