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　　2.Increases in the level of high-density lipoprotein (HDL)in the human bloodstream lower bloodstream cholesterol levels by increasing the body，s capacity to rid itself of excess cholestero1.Levels of HDL in the bloodstream of some individuals are significantly increased by a program of regular exercise and weight reduction. Which of the following can be correctly inferred from the statements above?
　　(A) Individuals who are underweight do not run any risk of developing high levels of cholesterol in the bloodstream.
　　(B) Individuals who do not exercise regularly have a high risk of developing high levels of cholesterol in the bloodstream late in lire.
　　(C) Exercise and weight reduction are the most effective methods of lowering bloodstream cholesterol levels in humans.
　　(D) A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.
　　(E) only regular exercise is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight.
　　3. A cost—effective solution to the problem of airport congestion is to provide high-speed ground transportation between major cities lying 200 to 500 miles apart.The successful implementation of this plan would cost far less than expanding existing airports and would also reduce the number of airplanes clogging both airports and airways. Which of the following，if true，could proponents of the plan above most appropriately cite as a piece of evidence for the soundness of their plan? (A) An effective high-speed ground--transportation system would require major repairs to many highways and mass-transit improvements. (B) One-half of all departing flights In the nation’s busiest airport head for a destination In a major city 225 miles away. (C) The majority of travelers departing from rural airports are flying to destinations in cities over 600 miles away. (D) Many new airports are being built in areas that are presently served by high-speed ground-transportation systems. (E) A large proportion of air travelers are vacationers who are taking long-distance flights.
　　4. The price the government pays for standard weapons purchased from military contractors is determined by a pricing method called "historical costing"Historical costing allows contractors to protect their profits by adding a percentage increase，based on the current rate of inflation，to the previous year’s contractual price. Which of the following statements，if true，is the best basis for a criticism of historical costing as an economically sound pricing method for military contracts? (A) The government might continue to pay for past inefficient use of funds.
　　(B) The rate of inflation has varied considerably over the past twenty years. (C) The contractual price w-II be greatly affected by the cost of materials used for the products. (D) Many taxpayers question the amount of money the government spends on military contracts. (E) The pricing method based on historical costing might not encourage the development of innovative weapons.
　　5. Which of the following best completes the passage below? Established companies concentrate on defending what they already have.Consequently, they tend not to be innovative themselves and tend to underestimate the effects of the innovations of others.The clearest example of this defensive strategy is the fact that .
　　(A) ballpoint pens and soft-tip markers have eliminated the traditional market for fountain pens，clearing the way for the marketing of fountain pens as luxury or prestige items (B) a highly successful automobile was introduced by the same company that had earlier introduced a model that had been a dismal failure (C) a once-successful manufacturer of slide rules reacted to the introduction of electronic calculators by trying to make better slide rules (D) one of the first models of modern accounting machines，designed for use in the banking industry, was purchased by a public library as well as by banks (E) the Inventor 0f a commonly used anesthetic did not intend the product to be used by dentists，who currently account for almost the entire market for that drug
　　6. Since the mayor’s publicity campaign for Greenville’s bus service began six months ago.morning automobile traffic into the midtown area of the city has decreased seven percent.During the same period，there has been an equivalent rise in the number of persons riding buses into the midtown area.Obviously, the mayor’s publicity campaign has convinced many people to leave their cars at home and ride the bus to work. Which of the following，if true，casts the most serious doubt on the conclusion drawn above?