[单项选择]
A Roof over Our Heads
Man has three basic needs: food, clothing, and shelter. If a man lives in a warm climate, clothing is not absolutely necessary. However, man cannot live without food, and, he has little chance of survival without shelter. Mankind needs shelter to protect him from the weather, wild animals, insects, and his enemies.
Long before man learned how to build houses, he looked for natural shelters, as the animals did. He found that he could protect himself by climbing up into trees or by crouching under the over-hanging edges of cliffs, or by crawling into caves. The first shelters or homes actually built by man were very simple. For his building materials, he used what he could find easily around him: rocks, tree branches, dried grasses, animal skins. It was a long time, however, before man began to build permanent shelters because, until man learned to farm, he lived by hunting. And, in order to follow game, he ha
A. Man’s three basic needs.
B. Development of roofs.
C. Man’s self-protection methods.
D. Man’s need for housing.