根据材料请回答 16～22 Plants and Mankind Botany, the study of plants, occupies a peculiar position in the history of human knowledge. We don't know what our Stone Age ancestors knew about plants, but from what we can observe of pre-industrial societies that still exist, a detailed learning of plants and their properties must be extremely ancient. This is logical. Plants are the basis of the food pyramid for all living things, even for other plants. They have always been enor-mously important to the welfare of people, not only for food, but also for clothing, weap-on, tools, dyes, medicines, shelter, and many other purposes. Tribes living today in the jungle of the Amazon recognize hundreds of plants and know many properties of each. To them botany has no name and is probably not even recognized as a special branch of'knowledge' at all. Unfortunately, the more industrialized we become the farther away we move from di-rect contact with plants, and the less distinct our knowledge of botany grows. Yet every-one comes unconsciously on an amazing amount of botanical knowledge, and few people will fail to recognize a rose, an apple or an orchid. When our Neolithic ancestors, living in the Middle East about 10,000 years ago, discovered that certain grasses could be harvested and their seeds planted for richer yields the next season, the first great step in a new asso-ciation of plants and humans was taken. Grains were discovered and from them flowed the marvel of agriculture: cultivated crops. From then on, humans would increasingly make their living from the controlled production of a few plants, rather than getting a little here and a little there from many varieties that grew wild, and the accumulated knowledge of tens of thousands of years of experience and intimacy with. plants in the wild would begin to fade away. 第 16 题 It is logical that a detailed learning of plants and their properties must be extreme-ly ancient.