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If we view a science as a body of systematized knowledge, then chemistry is usually called a natural science because it (26) knowledge of the natural world. At times we may wonder (27) there is no complete system (28) all of chemistry fits perfectly. Gaps in the present system, however, show that chemistry is still a(n) (29) subject and that we (30) all of its facts, laws, and theories. (31) , chemistry as a science is very much (32) us today, and its future holds the bright promise (33) much more to come. Man’s knowledge about himself and nature has grown into (34) sciences. The growth of the separate sciences has been more developmental than intentional. The separation of the natural sciences into physical and biological sciences, and physical sciences into physics and chemistry, happily (35) a larger body of knowledge into more manageable parts. At the same time we should remember that the concepts, techniques, and applications of the various sciences are interdependent and not exclusively a part of one science or (36) . In this (37) , chemistry is a key science among the natural sciences because everyone, (38) the area of natural science he wishes to pursue, needs at least an introduction to the principles and simpler applications of chemistry as a foundation for his specialty. Chemistry deals with the (39) of matter, changes in matter, the laws and principles (40) these changes, and the concepts and theories that interpret them.
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Directions: Write a composition on Changes in Farming in the U. S. , based on the information given in the table below. Farm Population (Million) Number of Farms (Million) Average Farm Size (acre) 1940s 32 6.3 170 1950s 24.5 5.6 230 1960s 17 4 300 1970s 9.5 2.9 360 1980s 6 2.5 450
W: Could you tell me something about the apartment you rentM: Well, it’s $ 1 300 a month, including heat and electricity. What does the woman want to do（）
SECTION A CONVERSATIONS In Sections A, B and C you will hear everything ONCE ONLY. Listen carefully and then answer the questions that follow. Mark the correct response for each question on your ANSWER SHEET.Questions 1 to 4 are based on the following conversation. At the end of the conversation, you will be given 20 seconds to answer the questions.Now listen to the conversation. How long is the shaft
M: Now, Miss Christina, I see that you are quite a heavy smoker. You told me you smoke about thirty a day. Well, my advice is quite simple: stop smoking. You know that cigarettes cause cancer and heart disease. Have you tried to give upW: Yes, lots of times. But I just find it impossible to stop.M: Well, in that case, let me suggest five things which you can do. First of all, if you smoke strong cigarettes, you should change to milder ones. But that won’t help you if you smoke more. So, secondly, don’t smoke as many cigarettes. Try to cut down by one or two every day. OK The next three points are to do with how you smoke. The most important is this: don’t breathe the smoke in. It’s when you breathe in the smoke that you do most damage to your health. Next, don’t keep the cigarette in your mouth all the time. Pat it in an ashtray when you are not smoking it. And finally, don’t smoke all the cigarette. The end of a cigarette is very dangerous to your health. So put the cigarette out after you have smoke half of it. All right Why does the man ask Christina not to smoke all the cigarette（）
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