1
Involving two people or groups who agree to help each other.
2
The part of the earth’s surface and atmosphere in which plants and animals can live.
3
A series of similar items in which each is almost the same as the ones next to it but the last is very different from the first.
4
When a part of one covers part of the other.
5
A person who is the same age or who has the same social status as you.
