Electric utilities pay less for low-quality coal per ton delivered than for high-quality coal. Yet more low-quality coal than high-quality coal must be burned to generate the same amount of electricity. Moreover, per ton of coal burned, low-quality coal generates more ash than does high-quality coal, and the disposal of ash is becoming more and more expensive.The considerations above, if true, most strongly support which of the following claims?
Letter to the editor: Our city plans to allow major commercial development along the south waterfront and, in so doing, to increase its tax revenue. But, to succeed commercially, the development would inevitably create far more road traffic than the existing roads to the waterfront can handle, causing serious congestion. Providing enough roads or public transportation to the area would cost far more than the city could gain from the increased tax revenue.Which of the following, if added to the city's plan, would be most likely to help solve the problem the letter describes?
In Asia, where palm trees are non-native, the trees’ flowers have traditionally been pollinated by hand, which has kept palm fruit productivity unnaturally low. When weevils known to be efficient pollinators of palm flowers were introduced into Asia in 1980, palm fruit productivity increased— by up to 50 percent in some areas—but then decreased sharply in 1984.Which of the following statements, if true, would best explain the 1984 decrease in productivity?
【OG20-P569-634题】Snowmaking machines work by spraying a mist that freezes immediately on contact with cold air. Because the sudden freezing kills bacteria, QuickFreeze is planning to market a wastewater purification system that works on the same principle. The process works only when temperatures are cold, however, so municipalities using it will still need to maintain a conventional system. Which of the following, if true, provides the strongest grounds for a prediction that municipalities will buy QuickFreeze's purification system despite the need to maintain a conventional purification system as well?
In Berinia, the age at which people could begin to drink alcohol legally used to be 18. In 1990, in an attempt to reduce alcohol consumption and thereby to reduce alcohol-related traffic deaths among Berinlans under 21, the legal drinking age was raised to 21. Alcohol-related traffic deaths among people under 21 have decreased significantly since 1990. Nevertheless, surveys show that people in that age-group drink just as much alcohol as they did before 1990.Which of the following, if true of Berinia, most helps to resolve the apparent discrepancy?
When a city experiences a sharp decline in population, the city's tax revenues, which pay for such city services as police protection and maintenance of water lines, also decrease. The area to be policed and the number and length of the water lines to be maintained, however, do not decrease. Attempting to make up the tax revenue lost by raising tax rates is not feasible, since higher tax rates would cause even more residents to leave.The information given most strongly supports which of the following general claims?
Perkins: According to an article I read, the woolly mammoth‘s extinction in North America coincided with a migration of humans onto the continent 12,000 years ago, and stone spearheads from this period indicate that these people were hunters. But the author's contention that being hunted by humans contributed to the woolly mammoth‘s extinction is surely wrong since, as paleontologists know, no spearheads have ever been found among the many mammoth bones that have been unearthed.Which of the following, if true, provides the strongest reason for discounting the evidence Perkins cites in arguing against the contention that being hunted by humans contributed to the North American extinction of woolly mammoths?