Botany, the study of plants, occupies a peculiar position in the history of human knowledge.

　　For many thousands of years it was the one field of awareness about which humans had anything more than the vaguest of insights. It is impossible to know today just what our Stone Age ancestors knew about plants, but from what we can observe of preindustrial 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, oyramid for all living things, even for other plants. They have always been enormously important to the welfare of people, not only for food, but also for clothing, weapons, tools, dyes, medicines, shelter, and a great many other purposes. Tribes living today in the jungles of the Amazon recognize literally hundreds of plants and know many properties of each. To them botany, as such, 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 direct contact with plants, and the less distinct our knowledge of botany grows. Yet everyone 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 association 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 take 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.

　　41 . Which of the following assumptions about early humans is expressed in the passage?

　　(A) They probably had extensive knowledge of plants.

　　(B) They divided knowledge into well-defined fields .

　　(C) They did not enjoy the study of botany. .

　　(D) They placed great importance on ownership of property.

　　42. The word "peculiar" in line 1 is closest in meaning to

　　(A) clear

　　(B) large

　　(C) unusual

　　(D) important

　　43. What does the comment "This is logical" in lines 5-6 mean ?

　　(A) There is no clear way to determine the extent of our ancestors knowledge of plants.

　　(B) It is not surprising that early humans had a detailed knowledge of plants .

　　(C) It is reasonable to assume that our ancestors behaved very much like people in preindustrial societies .

　　(D) Human knowledge of plants is well organized and very detailed.

　　44. The phrase "properties of each" in line 10 refers to each

　　(A) tribe

　　(B) hundred

　　(C) plant

　　(D) purpose

　　45.According to the passage, why has general knowledge of botany declined?

　　(A) People no longer value plants as a useful resource .

　　(B) Botany is not recognized as a special branch of science.

　　(C) Research is unable to keep up with the increasing number of plants.

　　(D) Direct contact with a variety of plants has decreased.

　　46. In line 15, what is the author s purpose in mentioning" a rose, an apple, or an orchid"?

　　(A) To make the passage more poetic

　　(B) To cite examples of plants that are attractive

　　(C) To give botanical examples that most readers will recognize

　　(D) To illustrate the diversity of botanical life

　　47. According to the passage, what was the first great step toward the practice  of agriculture ?

　　(A) The invention of agricultural implements and machinery

　　(B) The development of a system of names for plants

　　(C) The discovery of grasses that could be harvested and replanted

　　(D) The changing diets of early humans

　　48. The word "controlled" in line 19 is closest in meaning to

　　(A) abundant

　　(B) managed

　　(C) required

　　(D) advanced

　　49. The relationship between botany and agriculture is similar to the relationship between zoology (the study of animals) and

　　(A) deer hunting

　　(B) bird watching

　　(C) sheep raising

　　(D) horseback riding

　　50. Where in the passage does the author describe the benefits people derive from plants?

　　(A) Line 1

　　(B) Lines 6-8

　　(C) Lines 10-11

　　(D) Lines 13-15