Trees are very useful to man. They support the life old living things. Trees are needed for making paper, furnish and houses. They are used in everything. When w breathe and burn, we produce carbon dioxide. Trees replace this carbon dioxide with oxygen. The green leaves of trees absorb carbon dioxide and break it up into carbon and oxygen. The leaves keep carbon and release oxygen for the use of living beings. Trees prevent drought and floods. Man has cut down trees in large numbers and he is cutting more and more trees. Man must stop cutting more trees, otherwise he will suffer greatly.