Man can imitate things in natureand make new things to help us improve our living conditions. Take radar and saw for instance, radar is made on the basis that bat can identify object by searching ultrasoni
the concrete and bricks to build our houses, the materials to make bikes we ride, etc. , all come originally from have been making use of these natural supplies for thousands of years. With
Protection of the Environment Once man did not have to think about the protection of his environment. There were few people on the earth, and natural resources seemed to be things are differen