Big factories cause pollution.
Pollution is caused by big factories.
Tourists were leaving plastic bottles all over the park.
Plastic bottles were being left all over the park by tourists.
They are building a new recycling plant at the moment.
A new recycling plant is being built at the moment.
They make paper from wood.
Paper is made from wood.
The city council will reopen this old building as a museum.
This old building will be reopened as a museum by the city council.
The school had recycled 2 tons of paper by 2010.
2 tons of paper had been recycled by the school by 2010
They placed a bottle bank near my house last month.
A bottle bank was placed near my house last month.
The government has prohibited fishing in the area.
Fishing in the area has been prohibited by the government.
Plastic waste pollutes our beaches.
Our beaches are polluted by plastic waste.
They are building our new house so it's environmentally friendly.
Our new house is being built so it's environmentally friendly.
They dropped the first atomic bomb in Hiroshima.
The first atomic bomb was dropped in Hiroshima.
They make this material from recycled cans.
This material is made from recycled cans.