wangyilin888

13.(Z18)Manatees, aquatic mammals inhabiting Florida’s rivers and coastal waters, swim close to the surface and are frequently killed in collisions with boats.  To address the problem, boat traffic in manatee-populated waters is being required to maintain very low speeds.  Unfortunately, manatees are unable to hear low-pitched sounds and a boat’s sound lowers in pitch as the boat slows.  Therefore, this approach may in fact make things worse rather than better.

Which of the following, if true, casts most doubt on the conclusion?

A.        The areas where boats would have to maintain low speeds were decided partly on the basis of manatee-population estimates and partly from numbers of reported collisions between manatees and boats.
B.        Because the water hyacinth that manatees feed on grows best in water that is nearly still, water hyacinth beds can be disturbed or damaged by fast-moving boat traffic.
C.        Over the last several decades, boat traffic in Florida’s coastal waters has been increasing almost continuously and now represents the greatest threat to the endangered manatee population.
D.        The sound of a boat engine generally travels much further under water than it does through the air.
E.        When experimenters exposed manatees to the recorded sounds of boats moving at various speeds, the creatures were unable to discern the sounds over normal background noise.

wangyilin888

14.(Z18)Political Advertisement:
Mayor Delmont’s critics complain about the jobs that were lost in the city under Delmont’s leadership.  Yet the fact is that not only were more jobs created than were eliminated, but each year since Delmont took office the average pay for the new jobs created has been higher than that year’s average pay for jobs citywide.  So it stands to reason that throughout Delmont’s tenure the average paycheck in this city has been getting steadily bigger.

Which of the following, if true, most seriously weakens the argument in the advertisement?

A.        The unemployment rate in the city is higher today than it was when Mayor Delmont took office.
B.        The average pay for jobs in the city was at a ten-year low when Mayor Delmont took office.
C.        Each year during Mayor Delmont’s tenure, the average pay for jobs that were eliminated has been higher than the average pay for jobs citywide.
D.        Most of the jobs eliminated during Mayor Delmont’s tenure were in declining industries.
E.        The average pay for jobs in the city is currently lower than it is for jobs in the suburbs surrounding the city.

wangyilin888

15.(Z19)In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria’s roads but are involved in 12 percent of all highway fatalities.  The very largest trucks—those with three trailers—had less than a third of the accident rate of single-and double-trailer trucks.  Clearly, therefore, one way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks.

Which of the following, if true, most seriously weakens the argument?

A.        Partorian trucking companies have so far used triple-trailer trucks on lightly traveled sections of major highways only.
B.        No matter what changes Partoria makes in the regulation of trucking, it will have to keep some smaller roads off-limits to all large trucks.
C.        Very few fatal collisions involving trucks in Partoria are collisions between two trucks.
D.        In Partoria, the safety record of the trucking industry as a whole has improved slightly over the past ten year
E.        In Partoria, the maximum legal payload of a triple-trailer truck is less than three times the maximum legal payload of the largest of the single-trailer trucks.

wangyilin888

16.(Z19)Rabbits were introduced to Numa Island in the nineteenth century.  Overgrazing by the enormous population of rabbits now menaces the island’s agriculture.  The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere.  There is, however, a chance that the virus will infect the bilby, an endangered native marsupial.  The government’s plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

Which of the following, if true, most seriously weakens the argument?

A.        There is less chance that the virus will infect domestic animals on Numa than that it will infect bilbies.
B.        There are no species of animals on the island that prey on the rabbits.
C.        Overgrazing by rabbits endangers many of the plants on which bilbies feed.
D.        The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.
E.        There is no alternative means of reducing the rabbit population that would involve no threat to the bilby.

wangyilin888

17.(Z19)Mice that have been given morphine are very likely to develop blood poisoning because bacteria that normally reside in the intestine typically respond to morphine by migrating into the bloodstream.  However, when mice are given both morphine and the new drug naltrexone, blood poisoning is much less frequent, although it does still occur.  These results provide support for researchers’ prediction that naltrexone will turn out to be toxic to certain types of bacteria.

Which of the following, if discovered to be true, would most seriously weaken the support for the researchers’ prediction?

A.        After being administered to mice, naltrexone does not pass from the bloodstream into the intestine.
B.        Naltrexone inhibits morphine from triggering the migration of intestinal bacteria into the bloodstream.
C.        Mice that have been given naltrexone but not morphine have no greater risk of developing blood poisoning than do mice that have not been given either substance.
D.        The increased risk of blood poisoning is not the only harmful effect on mice of being given morphine.
E.        Conditions other than the presence of intestinal bacteria in the bloodstream can cause blood poisoning in mice.

wangyilin888

18.(Z20)Industrial accidents are more common when some of the people in safety-sensitive jobs have drinking problems than when none do.  Since, even after treatment, people who have had drinking problems are somewhat more likely than other people to have drinking problems in the future, any employer trying to reduce the risk of accidents should bar anyone who has ever been treated for a drinking problem from holding a safety-sensitive job.

Which of the following, if true, most seriously undermines the argument above?

A.        Some companies place employees who are being treated for drinking problems in residential programs and allow them several weeks of paid sick leave.
B.        Many accidents in the workplace are the result of errors by employees who do not hold safety-sensitive jobs.
C.        Workers who would permanently lose their jobs if they sought treatment for a drinking problem try instead to conceal their problem and continue working for as long as possible.
D.        People who hold safety-sensitive jobs are subject to stresses that can exacerbate any personal problems they may have, including drinking problems.
E.        Some industrial accidents are caused by equipment failure rather than by employee error.

wangyilin888

19.(Z20)A major chemical spill occurred five years ago at Baker’s Beach, the world’s sole nesting ground for Merrick sea turtles, and prevented nearly all the eggs laid that year from hatching.  Yet the number of adult female Merricks returning to lay their eggs at Baker’s Beach has actually increased somewhat since five years ago.  Clearly, environmentalists’ prediction that the world’s Merrick population would decline as a result of the spill has proven unfounded.

Which of the following, if true, most seriously undermines the argument offered in refutation of the environmentalists’ prediction?

A.        The chemical spill five years ago occurred at a time when there were neither Merrick sea turtles nor Merrick sea turtle eggs on Baker’s Beach.
B.        Female Merrick sea turtles begin returning to Baker’s Beach to lay their eggs when they are ten years old.
C.        Under normal conditions, only a small proportion of hatchling female Merrick sea turtles survive in the ocean until adulthood and return to lay their eggs at Baker’s Beach.
D.        Environmental pressures unrelated to the chemical spill have caused a significant decline in the population of one of the several species of sea birds that prey on Merrick sea turtle eggs.
E.        After the chemical spill, an environmental group rejected a proposal to increase the Merrick sea turtle population by transferring eggs from Baker’s Beach to nearby beaches that had not been affected by the spill.

Secret passwords are often used to control access to computers. When emoployees
As their initials or birth dates. To improve security, employers should assign ran-
domly generaied passwords to employees rather than allowing employees to make up their own

wangyilin888

20.(Z21)Which of the following, if true, most seriously undermines the conclusiun drawm above?

A.        if passwords are generated randomly, it is theoretically possible that employees will be assigned passwords that they might have selected on their own.
B.        Randomly generated passwords are so difficult for employees to recall that they often record the passwords in places where the passwords could be easily seen by others.
C.        Computer systems protected by passwords are designed to ignore commands that are entered by employees or others who use invalid passwords.
D.        In general, the higher the level of security maintained at the computer system, the more difficult it is for unauthorized users to obtain access to the system.
E.        Control of physical access to computers by the use of locked doors and guards should be used un addition to passwords in order to maintain security.

wangyilin888

21.(Z21)In recent years, networks of fiber-optic cable have been replacing electrical wire for transmitting telecommunications signals, Signals running through fiber-optic cables deteriorate, and wo the signals must be run through a piece of e3quiplent called a regenerator before being transmitted father. Light-Line is the leading manufacturer of signal regenerators. Therefore, Light-line is one of the companies that will most benefit if new long-distance fiber-optic telecommunications networks are constructed.

Which of the following, if true, casts the most doubt on the prediction about light-ling’sprospects?

A. Telecommunications signals sent along electrical wires can travel much Farther than signals transmitted through fiber-optic before needing to be
Regenerated.
B. Expanding its production of regenerators will require Light-line to spend proportionately more on labor and materials.
C. The volume of signals that a fiber-optic cable can carry is several Thousand times greater than the volume that can be carried by an electrical Wire of similar size.
D. There are technologies that enable telecommunications signals to be transmil
Without either wire or fiber-optic cable

F.        Several manufacturers are developing regenerator technologies that will allow to be transmitted many times farther than at present before requiring regeneration.

wangyilin888

22.(Z21)Rail Executive: Five years age we discontinued train service between Lamberton and its suburbs because low ridership caused total fares collected to be substantially lower than the cost of operating the service it is true that recent population growth in the suburban communities suggests increased potential ridership, neverthelesssince most of the newer residents own automobiles, restoring the train service this year would still result in serious deficits

Which of the following ,if true casts the most serious doubt on the rail executive’s argument?

A. Once train service along a given route has been discontinued ,there are substantial start-up costs associated with restoring service along that route
B. Most of the new residents of Lamberton’s suburbs do not need to
travel into Lamberton regularly for shopping or recreation
C. If train service were restored this with increased hours of service there would not be an increase mcrease in total ridership
D. A survey conducted last year showed that few people living in Lamberton or its suburbs support increased public funding for mass transportation.
E. Recently there have been sharp increases in parking fees in Lamberton and in highway tolls on major commuter routes.