题目内容
求曲线y=lnx在区间(2,6)内的一条切线，使该切线与直线x=2，x=6及曲线y=lnx所围图形的面积最小．
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Question 23 to 25 are based on the conversation you have just heard.
Modern Drugs Doctors, sixty years ago, could do little to help victims of polio. Serious cases usually ended in death. In 1955, a vaccine was developed that prevented the disease. Today, polio is no longer a major health problem. Many of the most important drugs that doctors prescribe today have been developed in the last 30 years. Modern drugs are complex, specific and powerful. People need to know more about drugs in order to use them safely. Early people discovered by accident that some of the plants growing around them seemed useful to heal sores, relieve pain, or even cure diseases. These plants were the first drugs. Now plants are still the source of some drugs. Quinine, for example, is a bitter-tasting drug used to treat the chills and fever of malaria and to reduce attacks of the disease. It is made from the bark of the cinchona tree, which grows in the Andes Mountains. The Indians of that region were the first to use the bark as a medicine. The Spanish people probably brought it to Europe in the early 1600s. Chemists learned how to get the pure drug from the bark and in 1944; it was made artificially in the laboratory. Other important drugs, such as hormones and vaccines, are obtained from animals. But most of the modern drugs come from chemical combinations worked out by research scientists. Most people never see drugs in their simple form as chemicals. Instead, they are seen as tablets, capsules or liquids that contain the drug and other ingredients. People use drugs to get different results. Some drugs attack the organism that causes a disease. They cure by killing the organism. Other drugs relieve what we call the symptoms of the disease: the headache, pain, fever or chills, and make the patient more comfortable. These constitute most over-the-counter drugs. People can get them in drug stores. It seems to the author that the medicine used by early people______.
Investment in the public sector, such as electricity, irrigation, quarrying, public services and transport (excluding vehicles, ships and planes) increased by about 10%, although the emphasis moved to transport and away from the other sectors mentioned. Trade and services recorded a 16 --17 % investment growth, including a 30% increase in investment in business premises. Industrial investment is estimated to have risen by 8%. Although the share of agriculture in total gross investment in the economy continued to decline, investment grew by 9% in absolute terms, largely spurred on by a 23% expansion of investment in agricultural equipment. Housing construction had 12% more invested in it in 1964, not so much owing to increased demand, as to fears of impending new taxes and limitation of building. Total consumption in real terms rose by close on 11% during 1964, and per capita personal consumption by under 7%, as in 1963. The undesirable trend towards a rapid rise in consumption, evident in previous years, remained unaltered. Since at current prices consumption rose by 16% and disposable income by 13%, there was evidently a fall in the rate of saving in the private sector of the economy. Once again consumption patterns indicated a swift advance in the standard of living. Expenditure on food, especially bread and staple items, declined in significance, although consumption of fruit increased. Outlay on furniture and household equipment, health, eduction and recreation continued to increase. The greatest proof of altered living standards was the rapid expansion of expenditure on transport (including private cars) and personal services of all kinds, which occurred during 1964. The progressive affluence of large sectors of the public was demonstrated by the changing composition of durable goods purchased. Saturation point was rapidly being approached for items such as the first household radio, gas cookers, and electric refrigerators, whereas increasing purchases of automobiles and television sets were registered. From this passage, we may infer that the people of the country were ______.
Modern Drugs Doctors, sixty years ago, could do little to help victims of polio. Serious cases usually ended in death. In 1955, a vaccine was developed that prevented the disease. Today, polio is no longer a major health problem. Many of the most important drugs that doctors prescribe today have been developed in the last 30 years. Modern drugs are complex, specific and powerful. People need to know more about drugs in order to use them safely. Early people discovered by accident that some of the plants growing around them seemed useful to heal sores, relieve pain, or even cure diseases. These plants were the first drugs. Now plants are still the source of some drugs. Quinine, for example, is a bitter-tasting drug used to treat the chills and fever of malaria and to reduce attacks of the disease. It is made from the bark of the cinchona tree, which grows in the Andes Mountains. The Indians of that region were the first to use the bark as a medicine. The Spanish people probably brought it to Europe in the early 1600s. Chemists learned how to get the pure drug from the bark and in 1944; it was made artificially in the laboratory. Other important drugs, such as hormones and vaccines, are obtained from animals. But most of the modern drugs come from chemical combinations worked out by research scientists. Most people never see drugs in their simple form as chemicals. Instead, they are seen as tablets, capsules or liquids that contain the drug and other ingredients. People use drugs to get different results. Some drugs attack the organism that causes a disease. They cure by killing the organism. Other drugs relieve what we call the symptoms of the disease: the headache, pain, fever or chills, and make the patient more comfortable. These constitute most over-the-counter drugs. People can get them in drug stores. It is implied in the passage that most drugs can be______.
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