Conservation is the (1)________ and preservation of natural resources, so that they can continue (2)________and enjoyed. In the past, most people believed that the world's (3) _______ could never be used up. Today, we know that (4) _______ is not true. An important part of conservation is the (5) _______ of waste - waste of forests, soil, wild-life, (6) _______ and human lives. As important is the fight (7) ________ pollution of our (8)_______, in particular, the dirtying and poisoning of air and water. Conservation is (9)_______ concerned with the reclaiming of land by (10) _______ deserts, draining swamps or pushing back the sea.