1
Adjective related to the natural conditions.
2
The action of polluting.
3
All plants, animals and people in an area and their relationships.
4
Animals and plants living in natural conditions.
5
A structure with a roof and walls.
6
The quality of being acid.
7
Unhealthy condition caused by an infection or disorder.
8
A covering on a surface.
9
Likely to cause harm.
10
Combination of substances.
11
The top covering of the Earth where plants grow.
