Yay. Grammar.
1. Those cars are built to be less harmful to the environment.
2. The animals in the wildlife park aren't hunted.
3. The water on the river is not frozen because it’s not cold enough.
4. Rubber is used to make erasers.
5. Plastic bottles aren’t recycle at our recycling center.
6. These plants grow in a greenhouse. Or, These plants have grown in a greenhouse.
7. Water isn’t sold in plastic bottles at that store.