wangyilin888

18.(Z)The traditional treatment of strep infections has been a seven-day course of antibiotics, either penicillin or erythromycin. However, since many patients stop taking those drugs within three days, reinfection is common in cases where these drugs are prescribed. A new antibiotic requires only a three-day course of treatment. Therefore, reinfection will probably be less common in cases where the new antibiotic is prescribed than in cases where either penicillin or erythromycin is prescribed.

Which of the following, if true, most strengthens the argument?
Tricky!!
A.        Some of people who are allergic to penicillin are likely to be allergic to the new antibiotic.
B.        A course of treatment with the new antibiotic costs about the same as a course of treatment with either penicillin or erythromycin.
C.        The new antibiotic has been shown to be effective in eradicating bacterial infections other than strep.
D.        Some physicians have already begun to prescribe the new antibiotic instead of penicillin or erythromycin for the treatment of some strep infections
E.        Regardless of whether they take a traditional antibiotic or the new one, most patients feel fully recovered after taking the drug for three days.

wangyilin888

19.(Z)In response to viral infection, the immune systems of mice typically produce antibodies that destroy the virus by binding to proteins on its surface.  Mice infected with a herpesvirus generally develop keratitis, a degenerative disease affecting part of the eye.  Since proteins on the surface of cells in this part of the eye closely resemble those on the herpesvirus surface, scientists hypothesize that these cases of keratitis are caused by antibodies to herpesvirus.

Which of the following, if true, gives the greatest additional support to the scientists’ hypothesis?

A.        Other types of virus have surface proteins that closely resemble proteins found in various organs of mice.
B.        There are mice that are unable to form antibodies in response to herpes infections, and these mice contract herpes at roughly the same rate as other mice.
C.        Mice that are infected with a herpesvirus but do not develop keratitis produce as many antibodies as infected mice that do develop keratitis.
D.        There are mice that are unable to form antibodies in response to herpes infections, and these mice survive these infections without ever developing keratitis.
E.        Mice that have never been infected with a herpesvirus can sometimes develop keratitis.

wangyilin888

20.(Z) 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 from feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. Therefore, if the population of these other species were increased, the number of ticks acquiring the bacterium and hence the number of people contracting Lyme disease would likely decline.

Which of the following, if true, most strengthens the argument?

A.        Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.
B.        There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.
C.        A deer tick feeds only once while in the larval stage.
D.        A single host animal can be the source of bacterium for many tick larvae.
E.        None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans

wangyilin888

练习题：
1. The town of Stavanger, Norway, was quiet and peaceful until early 1960’s, when Stavanger became Norway’s center for offshore oil exploration. Between then and now, violent crime and vandalism in Stavanger have greatly increased. Clearly, these social problems are among the results of Stavanger’s oil boom.
  
Which of the following, if it occurred between the early 1960’s and now, gives the strongest support to the argument above?

(A) The people of Stavanger rarely regret that their town was chosen to be Norway’s center for offshore oil exploration.
(B) Norwegian sociologists expressed grave concern about the increase in violent crime and vandalism in Stavanger.
(C) Violent crime and vandalism have remained low in Norwegian that had no oil boom.
(D) Nonviolent crime, drug addiction, and divorce in Stavanger increased approximately as much as violent crime and vandalism did.
(E) The oil boom necessitated the building of wider roads for the increased traffic in Stavanger.

wangyilin888

2. Airline: Newly developed collision-avoidance systems, although not fully tested to discover potential malfunctions, must be installed immediately in passenger planes. Their mechanical warnings enable pilots to avoid crashes.

Pilots: Pilots will not fly in planes with collision-avoidance systems that are not fully tested. Malfunctioning systems could mislead pilots, causing crashes.

The pilots’ objection is most strengthened if which of the following is true?
(A) It is always possible for mechanical devices to malfunction.
(B) Jet engines, although not fully tested when first put into use, have achieved exemplary performance and safety records.
(C) Although collision-avoidance systems will enable pilots to avoid some crashes, the likely malfunctions of the not-fully-tested systems will cause even more crashes.
(D) Many airline collisions are caused in part by the exhaustion of overworked pilots.
(E) Collision-avoidance systems, at this stage of development, appear to have worked better in passenger planes than in cargo planes during experimental flights made over a six-month period.

wangyilin888

3. Two decades after the Emerald River Dam was built, none of the eight fish species native to the Emerald River was still reproducing adequately in the river below the dam. Since the dam reduced the annual range of water temperature in the river below the dam from 50 degrees to 6 degrees, scientists have hypothesized that sharply rising water temperatures must be involved in signaling the native species to begin the reproductive cycle.

Which of the following statements, if true, would most strengthen the scientists’ hypothesis?

(A) The native fish species were still able to reproduce only in side streams of the river below the dam where the annual temperature range remains approximately 50 degrees.
(B) Before the dam was built, the Emerald River annually overflowed its banks, creating backwaters that were critical breeding areas for the native species of fish.
(C) The lowest recorded temperature of the Emerald River before the dam was built was 34 degrees, whereas the lowest recorded temperature of the river after the dam was built has been 43 degrees.
(D)Nonnative species of fish, introduced into the Emerald River after the dam was built, have begun competing with the declining native fish species for food and space.
(E) Five of the fish species native to the Emerald River are not native to any other river in North America.

wangyilin888

4. In recent years many cabinetmakers have been winning acclaim as artists. But since furniture must be useful, cabinetmakers must exercise their craft with an eye to the practical utility of their product. For this reason, cabinetmaking is not art.

Which of the following is an assumption that supports drawing the conclusion above from the reason given for that conclusion?

(A) Some furniture is made to be placed in museums, where it will not be used by anyone.
(B) Some cabinetmakers are more concerned than others with the practical utility of the products they produce.
(C) Cabinetmakers should be more concerned with the practical utility of their products than they currently are.
(D) An object is not an art object if its maker pays attention to the object’s practical utility.
(E) Artists are not concerned with the monetary value of their products.

wangyilin888

5. Since the routine use of antibiotics can give rise to resistant bacteria capable of surviving antibiotic environments, the presence of resistant bacteria in people could be due to the human use of prescription antibiotics. Some scientists, however, believe that most resistant bacteria in people derive from human consumption of bacterially infected meat.

Which of the following statements, if true, would most significantly strengthen the hypothesis of the scientists?

(A) Antibiotics are routinely included in livestock feed so that livestock producers can increase the rate of growth of their animals.
(B) Most people who develop food poisoning from bacterially infected meat are treated with prescription antibiotics.
(C) The incidence of resistant bacteria in people has tended to be much higher in urban areas than in rural areas where meat is of comparable quality.
(D) People who have never taken prescription antibiotics are those least likely to develop resistant bacteria.
(E) Livestock producers claim that resistant bacteria in animals cannot be transmitted to people through infected meat.

wangyilin888

6. Male bowerbirds construct elaborately decorated nests, or bowers. Basing their judgment on the fact that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, researchers have concluded that the bowerbirds’ building styles are a culturally acquired, rather than a genetically transmitted, trait.

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

(A) There are more common characteristics than there are differences among the bower-building styles of the local bowerbird population that has been studied most extensively
(B) Young male bowerbirds are inept at bower-building and apparently spend years watching their elders before becoming accomplished in the local bower style.
(C) The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.
(D) Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.
(E) It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.

wangyilin888

7. Many breakfast cereals are fortified with vitamin supplements. Some of these cereals provide 100 percent of the recommended daily requirement of vitamins. Nevertheless, a well-balanced breakfast, including a variety of foods, is a better source of those vitamins than are such fortified breakfast cereals alone.

Which of the following, if true, would most strongly support the position above?

(A) In many foods, the natural combination of vitamins with other nutrients makes those vitamins more usable by the body than are vitamins added in vitamin supplements.
(B) People who regularly eat cereals fortified with vitamin supplements sometimes neglect to eat the foods in which the vitamins occur naturally.
(C)Foods often must be fortified with vitamin supplements because naturally occurring vitamins are removed during processing.
(D) Unprocessed cereals are naturally high in several of the vitamins that are usually added to fortified breakfast cereals.
(E) Cereals containing vitamin supplements are no harder to digest than similar cereals without added vitamins.