Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these other species were increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.
Which of the following would it be most important to ascertain in evaluating the argument?
1. Lyrne disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these other species were increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.
A. Whether populations of the other species on which deer tick larvae feed are found also inhabited by white footed mice.
B. Whether the size of the deer tick population is currently limited by the availability of animals for the tick’s larval stage to feed on.
C. Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice
D. Whether deer ticks were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed
E. Whether the other species on which deer tick larvae feed harbor any other bacteria transmit to humans
答案不是D
2. Every fall Croton’s jays migrate south. The jays always join flocks of migrating crookbeaks with which they share the same summer and winter territories. If a jay becomes separated from the crookbeaks it is accompanying, it wanders until it comes across another flock of crookbeaks. Clearly, therefore, Croton’s jays lack the navigational ability to find their way south on their own.
Which of the following, if true, most strengthens the argument above?
A. Croton’s jays lay their eggs in the nests of the crookbeaks, which breed upon completing their southern migration
B. The three species most closely related to crookbeaks do not migrate at all.
C. In the spring, Croton’s jays migrate north in the company of Tattersall warblers.
D. Species other than Croton’s jays occasionally accompany flocks of migrating crookbeaks.
E. In the spring, crookbeaks migrate north before Croton’s jays do.
答案不是D
3. Following several years of declining advertising sales, the Greenville Times reorganized its advertising sales force two years ago. Before the reorganization, the sales force was organized geographically, with some sales representatives concentrating on city-center businesses and other concentrating on different outlying regions. The reorganization attempted to increase the sales representatives’ knowledge of clients’ business by having each sales representative deal with only one type of industry of retailing. Afger the reorganization, advertising sales increased.
A. Two years ago, what proportion of the Greenville Time’s total revenue was generated by advertising sales?
B. Has the circulation of Greenville Times increased substantially in the last two years?
C. Has there been a substantial turnover in personnel in the advertising sales force over last two years?
D. Before the reorganization, has sales representatives found it difficult to keep up with relevant developments in all the types of businesses to which they were assigned?
E. Has the economy in Greenville and the surrounding regions been growing rapidly over the last two year?
答案是什么A?why?
4. Which of the following most logically complete the argument?
When people engage in activities that help others, their brain releases endorphins, the brain’s natural opiates, which include in people a feeling of well-being. It has been suggested that regular release of endorphins increases people’s longevity, and a statistic on adults who regularly engage in volunteer work helping others show that they live longer, on average, than adults who do not volunteer. However, that statistic would be what we would expect even if volunteering does not boost longevity, because____
A. in the communities studies, women were much more likely to do regular volunteer work than men were, and women tend to live longer than men do
B. the number of yound adults who do regular volunteer work is on the increase
C. the feelings of well-being induced by endorphins can, at least for a time, mask the symptons of various conditions and diseases,provided the symotons are mild
D. It is rare for a person to keep up a regular schedule of volunteer work throughout his or her life.
E. Some people find that keeping a commitment to do regular volunteer work becomes a source of stress in their lives.