There ___ lots of litter by the river, but now it is clean.

People ___ plastic bags in this shop, but now they bring cloth bags.

This field ___ a rubbish dump.

We ___ see many birds here, but now wildlife is coming back.

Cars ___ make the air dirty on this road.

The children ___ clean up the beach every month, but now they do.

My grandpa ___ walk through a forest here.

This pond ___ have frogs before the pollution.

There ___ many factories near the town.

People ___ throw bottles into the recycle bin, but now they do.

The park ___ look dirty, but now it looks beautiful.

We ___ have a wildlife club at school, but now we do.

to / The / used / be / river / dirty.

didn’t / bottles. / use / to / recycle / They

river. / litter / used / be / to / by / the / There

use / to / many / here. / didn’t / birds / We / see