Answer:
In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique while others talk of a "plurality of worlds".
They give us informations about our ancestors and how did they live and what did they do and than compare it to present way's of life.
Answer:
Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy
Explanation:
We should grow many trees.If we don't the world will warm in the next 20-80 years.
