类别：地质类 真题 150822CN-P1
Title：Attempts at Determining Earth’s Age
Since the dawn of civilization, people have been curious about the age of Earth. In addition, we have not been satisfied in being able to sate merely the relative geologic age of a rock or fossil. Human curiosity demands that we know actual age in years.
Geologists working during the nineteenth century understood rock bodies, they would have to concentrate on natural processes that continue at a constant rate and that also leave some sort of tangible record in the rocks. Evolution is one such process, and geologist Charles Lyell (1797-1875) recognized this. BY comparing the amount of evolution exhibited by marine mollusks then, Lyell estimated that 80 million years had elapsed since the beginning of the Tertiary Period. He came astonishingly close to the mark, since it was actually about 65 million years. However, for older sequence of evolutionary development, estimates based on parts in the fossil record. Rates of evolution for many orders of plants and animals were not well understood.
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类别：农业类 真题 140316CN-P3
Title：Agricultural Society in Eighteenth-Century British America
In the northern American colonies, especially New England, tight-knit farming families, organized in communities of several thousand people, dotted the landscape by the mid-eighteenth century. New Englanders staked their future on a mixed economy. They cleared forests for timber used in barrels, ships, houses, and barns. They plumbed the offshore waters for fish to feed local populations. And they cultivated and grazed as much of the thin-soiled, rocky hills and bottomlands as they could recover from the forest.
The farmers of the middle colonies-Pennsylvania, Delaware, New Jersey, and New York-set their wooden plows to much richer soils than New Englanders did. They enjoyed the additional advantage of setting an area already partly cleared by Native Americans who had relied more on agriculture than had New England tribes. Thus favored, mid-Atlantic farm families produced modest surpluses of corn, wheat, beef, and pork. By the mid-eighteenth century, ships from New York and Philadelphia were carrying these foodstuffs not only to the West Indies, always a primary market, but also to areas that could no longer feed themselves-England, Spain, Portugal, and even New England.
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类别：社会类 真题 140816CN-P1
Title：Hunting and the Setting of Inner Eurasia
Inner Eurasia refers to the large continental area extending from Russia in the west to the Pacific Ocean, and to the north of Iran, India, and most of China. The first systematic colonization of parts of Inner Eurasia occurred about 80,000 to 90,000 years ago, which is relatively late in human history compared with Africa, Europe, and southern Asia. Why was it difficult to settle?
The long, cold, arid winters of this region’s steppes (grass covered plains) poised two distinctive problems for human settlers. The first was hot to keep warm. Humans may have used fire even a million years ago. Presumably their ability to scavenge animal carcasses meant that they could use skins or furs for warmth. However, there are no signs of hearths before about 200,000 years ago. This suggests that humans used fire opportunistically and had not yet domesticated it enough to survive the harsh winters of Ice Age InnerEurasia.
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