1.The German didn’t build this factory during the Second World War.

→ This factory wasn’t built (by the Greens) during the Second World War.

2.The Greens are going to paint this house and these cars for Christmas Day.

→ This house and these cars are going to be painted for Christmas day by the Greens.

3. Ann had fed the cats before she went to the cinema.

→ The cats had been fed (by Ann) before she went to the cinema.

4.The students have discussed the pollution problems since last week.

→ The pollution problems have been discussed (by the students) since last week.

5.Have the thieves stolen the most valuable painting in the national museum?

→ Has the most valuable painting in the national museum been stolen (by the thieves) ?

1. The factory was built by the German during the Second World War.

2. This house and these cars are going to be painted by the Greens for Chirstmas Day.

3. The cats had been fed by Ann before she went to the cinema.

4. The pullution problems have been discussed by the students since last week.

5. Has the most valueble in the national museum been stolen by the thieves?