4月10日逻辑题目

韩小宁

1、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.

2、Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive. Between 1994 and 1996, the number of RDS radio stations in Verdland increased from 250 to 600. However, since the number of RDS-equipped radios in Verdland was about the same in 1996 as in 1994, the number of Verdlanders receiving the special program information probably did not increase significantly.

Which of the following is an assumption on which the argument depends?

A) Few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.  
B) In 1996 most Verdlanders who lived within the listening area of an RDS station already had a radio equipped to receive RDS.  
C) Equipping a radio station with RDS technology does not decrease the station's listening area.  
D) In 1996 Verdlandres who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.  
E)The RDS radio stations in Verdland in 1996 did not all offer the same type of programming.  

3、A company plans to develop a prototype weeding machine that uses cutting blades with optical sensors and microprocessors that distinguish weeds from crop plants by differences in shade of color. The inventor of the machine claims that it will reduce labor costs by virtually eliminating the need for manual weeding.

Which of the following is a consideration in favor of the company's implementing its plan to develop the prototype?

A) There is a considerable degree of variation in shade of color between weeds of different species.  
B) The shade of color of some plants tends to change appreciably over the course of their growing season.  
C) When crops are weeded manually, overall size and leaf shape are taken into account in distinguishing crop plants from weeds.  
D) Selection and genetic manipulation allow plants of virtually any species to be economically bred to have a distinctive shade of color without altering their other characteristics.  
E) Farm laborers who are responsible for the manual weeding of crops carry out other agricultural duties at times in the growing season when extensive weeding is not necessary.

4、In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear radio collars. When, as often happens, a collar slips off, it is put back on. Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart. Female rhinoceroses that have been frequently recollared have significantly lower fertility rates than uncollared females. Probably, therefore, some substance in the tranquilizer inhibits fertility.

In evaluating the argument, it would be most useful to determine which of the following?

A) Whether there are more collared female rhinoceroses than uncollared female rhinoceroses in the park  
B) How the tranquilizer that is used for immobilizing rhinoceroses differs, if at all, from tranquilizers used in working with other large mammals  
C) How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars  
D) Whether male rhinoceroses in the wildlife park lose their collars any more often than the park's female rhinoceroses do  
E) Whether radio collars are the only practical means that park rangers have for tracking the movements of rhinoceroses in the park  

5、The price the government pays for standard weapons purchased from military contractors is determined by a pricing method called "historical costing" Historical costing allows contractors to protect their profits by adding a percentage increase, based on the current rate of inflation, to the previous year's contractual price.

Which of the following statements, if true, is the best basis for a criticism of historical costing as an economically sound pricing method for military contracts?

A) The government might continue to pay for past inefficient use of funds.  
B) The rate of inflation has varied considerably over the past twenty years.  
C) The contractual price w-II be greatly affected by the cost of materials used for the products.  
D) Many taxpayers question the amount of money the government spends on military contracts.  
E) The pricing method based on historical costing might not encourage the development of innovative weapons.