30. Joyce： Three years ago the traffic commission modified our town's busiest intersection for better visibility， a commendable effort to cut down on traffic accidents there. Gary： Over the past three years there have been more， not fewer， traffic accidents per week at that intersection， so the modification has increased the likelihood of accidents there
The answer to which of the following questions would be most useful in evaluating Gary's argument?
(A) What proportion of the town's drivers involved in accidents that occurred prior to the modification suffered personal injury in their accidents?
(B) How long， on average， had the members of the traffic commission held their offices when the modification was implemented?
(C) Do a majority of the town's residents approve of the traffic commission's overall performance?
(D) What measures have nearby towns taken within the last three years in order to improve visibil-ity at dangerous intersections?
(E) How has the volume of traffic at the town's busiest intersection changed over the last three years?
31. Women make up the majority of the population in the country， and many of the prescriptions written by doctors for tranquilizers are for women patients. The testing of these drugs for efficacy and the calibration of recommended doses， however， was done only on men. Not even the animals used to test toxicity were female.
The statements above， if true， best support which of the following as a conclusion?
(A) Some tranquilizers are more appropriately pre-scribed for women than for men.
(B) There have been no reports of negative side effects from prescribed tranquilizers in women
(C) Tranquilizers are prescribed for patients in some instances when doctors do not feel confident of their diagnoses.
(D) The toxicity of drugs to women is less than the toxicity of the same drugs to men.
(E) Whether the recommended dosages of tranquil-izers are optimal for women is not known.
32. Gray wolves have been absent from a large national park for decades. Park officials wish to reestablish the wolves without jeopardizing any existing species of wildlife there. Since the park contains adequate prey for the wolves and since the wolves avoid close contact with people， reintroducing them would serve the officials' purpose without seriously jeopardizing visitors' safety.
Each of the following， if true， strengthens the argument above EXCEPT：
(A) The park is so large that wolves will not need to venture into areas frequented by people.
(B) Rabies is very rare in wolves， and there have been no verified cases of serious human injuries from nonrabid wild wolves since records have been kept.
(C) Ranchers in the region near the park have expressed concern that gray wolves， if reintro-duced， would sometimes prey on their livestock.
(D) Predation by gray wolves on elk in the park is likely to improve the health and viability of the park's elk population as a whole by reducing malnutrition among the elk.
(E) Wolves do not prey on animals of any endangered species that currently inhabit the park.
33. Osteoporosis is a disease that reduces bone mass， lead-ing to fragile bones that break easily. Current treat-ments for osteoporosis such as estrogen or calcitonin help prevent further loss of bone but do not increase bone mass. Since fluoride is known to increase bone mass， administering fluoride to osteoporosis patients would therefore help make their bones less susceptible to breaking.
Which of the following， if true， most seriously weakens the argument above?
(A) Most people who suffer from osteoporosis are not aware that administration of fluoride can increase bone mass.
(B) Fluoride is added to drinking water in many locations in order to strengthen the teeth of people who drink the water.
(C) The risk of contracting osteoporosis and other degenerative bone diseases is lessened by exer-cise and an adequate intake of calcium.
(D) Unlike administration of fluoride， administration of estrogen or calcitonin is known to cause undesirable side effects for many people.
(E) The new bone mass that is added by the admin-istration of fluoride is more brittle and less elastic than normal bone tissue.
参考答案： 30.E 31.E 32.C 33.E