29. The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year, Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following, if true, would most seriously weaken the health officials’ explanation for the lower incidence of the disease?
(A) Many new water-treatment plants have been built in the last five years in the rural county.
(B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
(C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
(D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
(E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.
正确答案是C,能帮我解释一下逻辑关系吗?有点confusing...另外,A答案不对,我自己考虑了一下,可不可以这样想:即便是那些plant被built了5年,也不一定就是一built马上就有效果,说不定刚好是这一年出现了效果而已,但并不是导致decrease的直接原因?(请指正我这样想是否可以)
30. 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 will 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.
选A。请帮我解释一下E.是不是对于innovative weapones定价的政策,贮于引入了新概念,不该掺乎进来?
38.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 of 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
选C。这个我没有太明白,请帮我解释一下答案。
期待回复,非常感谢!
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