Springfield Fire Commissioner: the vast majority of false fire alarms
are prank calls made anonymously from fire alarm boxes on street
corners. Since virtually everyone has access to a private telephone,
these alarm boxes have outlived their usefulness. Therefore, we
propose to remove the boxes. Removing the boxes will reduce the
number of prank calls without hampering people's ability to report a fire.
Which of the following, if true, most strongly supports the claim that the
proposal, if carried out, will have the announced effect?
The fire department traces all alarm calls made from private tele-phones and records where they came from.
Maintaining the fire alarm boxes costs Springfield approximately five million dollars annually.
A telephone call can provide the fire department with more informa-tion about the nature and size of a fire than can an alarm placed from an alarm box.
Responding to false alarms significantly reduces the fire depart-ment's capacity for responding to fires.
On any given day, a significant percentage of the public telephones in Springfield are out of service.
Scientists have made genetic modifications to cotton to increase its resistance to insect pests. According to farmers' report, the amount of insecticide needed per acre to control insect pests was only slightly lower for those who tried the modified seed than for those who did not. Therefore, since the modified seed costs more than ordinary seed without producing yields of higher market value, switching to the modified seed would be unlikely to benefit most cotton farmers economically.
Which of the following would it be most useful to know in order to evaluate the argument?
Whether farmers who tried the modified cotton seed had ever tried growing other crops from genetically modified seed
Whether the insecticides typically used on ordinary cotton tend to be more expensive than insecticides typically used on other crops
Whether for most farmers who grow cotton it is their primary crop
Whether the farmers who have tried the modified seed planted as many acres of cotton, on average, as farmers using the ordinary seed did
Whether most of the farmers who tried the modified seed did so because they had previously had to use exceptionally large quantities of insecticide
这个题也不太理解答案是D
The Earth's rivers constantly carry dissolved salts into its oceans.Clearly,therefore, by taking the resulting increase in salt levels in the oceans over the past hundred years and then determining how many centuries of such increases it would have taken the oceans to reach current salt levels from a hypothetical initial salt-free state, the maximum age of the Earth's oceans can be accurately estimated.
Which of the following is an assumption on which the argument depends?
The quantities of dissolved salts deposited by rivers in the Earth's oceans have not been unusually large during the past hundred years.
At any given time, all the Earth's rivers have about the same salt levels.
There are salts that leach into the Earth's oceans directly from the ocean floor.
There is no method superior to that based on salt levels for estimating the maximum age of the Earth's oceans.
None of the salts carried into the Earth's oceans by rivers are used up by biological activity in the oceans.
还有这个，也不会。。。
