1.(Z)In 1960’s studies of rats, scientists found that crowding increases the number of attacks among the animals significantly. But in recent experiments in which rhesus monkeys were placed in crowded conditions, although there was an increase in instances of “coping” behavior—such as submissive gestures and avoidance of dominant individuals—attacks did not become any more frequent. Therefore it is not likely that, for any species of monkey, crowding increases aggression as significantly as was seen in rats.
Which of the following, if true, most strengthens the argument?
A. All the observed forms of coping behavior can be found among rhesus monkeys living in uncrowded conditions.
B. In the studies of rats, nondominant individuals were found to increasingly avoid dominant individuals when the animals were in crowded conditions.
C. Rhesus monkeys respond with aggression to a wider range of stimuli than any other monkeys do.
D. Some individual monkeys in the experiment were involved in significantly more attacks than the other monkeys were.
E. Some of the coping behavior displayed by rhesus monkeys is similar to ehavior rhesus monkeys use to bring to an end an attack that has begun.
2.(Z)It is crucially important to farmers that the herbicides they use to control weeds not damage their crops. One very effective herbicide is safe for corn, but soybeans are damaged even by the herbicide’s residue, which remains in the soil more than a year after the herbicide is applied. Soybeans and corn are not sown together in the sameriled;nevertheless, most farmers are reluctant to use the herbicide on their corn.
Which of the following, if true, provides the strongest justification for the farmers’ reluctance?
A. The residue of the herbicide in the soil a year after application is
not enough to control most weeds effectively.
B. To maint ain the nutrients in the soil, corn and soybeans are oftenplanted in A riled in alternate years.
C. The demand for soybeans is growing faster than is the demand for corn.
D. For maximum yield, soybean plants are grown closer together to
each other than are corn plants.
E. The application of herbicides is less critical for soybean than forcorn crops.
3. Country Y uses its scarce foreign-exchange reserves to buy scrap iron for recycling into steel. Although the steel thus produced earns more foreign exchange than it costs, that policy is foolish. Country Y’s own territory has vast deposits of iron ore, which can be mined with minimal expenditure of foreign exchange.
Which of the following, if true, provides the strongest support for Country Y’s policy of buying scrap iron broad?
(A) The price of scrap iron on international markets rose significantly in 1987.
(B) Country Y’s foreign-exchange reserves dropped significantly in 1987.
(C) There is virtually no difference in quality between steel produced from scrap iron and that produced from iron ore.
(D) Scrap iron is now used in the production of roughly half the steel used in the world today, and experts predict that scrap iron will be used even more extensively in the future.
(E) Furnaces that process scrap iron can be built and operated in Country Y with substantially less foreign exchange than can furnaces that process iron ore.
4. There is a great deal of geographical variation in the frequency of many surgical procedures—up to tenfold variation per hundred thousand between different areas in the numbers of hysterectomies, prostatectomies, and tonsillectomies.
To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following?
(A) A local board of review at each hospital examines the records of every operation to determine whether the surgical procedure was necessary.
(B) The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered.
(C) There are several categories of surgical procedure (other than hysterectomies, prostatectomies, and tonsillectomies) that are often performed unnecessarily.
(D) For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or whether alternative treatment would have succeeded.
(E) With respect to how often they are performed unnecessarily, hysterectomies, prostatectomies, and tonsillectomies are representative of surgical procedures in general.
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