Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35.

______(31) is the safeguarding and preservation of natural ______(32), so that they can continue to be used and enjoyed. In the past, most people believed that the world‟s resources could never be ______(33). Today, we know that this is not true. An important part of conservation is the ______(34) of waste - waste of forests, soil, minerals, wild-life, and human lives. As important is the fight against pollution of our environment, in particular, the dirtying and poisoning of air and water. Conservation is also concerned ______(35) the reclaiming of land by irrigating deserts, draining swamps, or pushing back the sea.