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题目材料：
Trees play an important role in controlling the amount of carbon dioxide in the atmosphere, since they take up carbon dioxide from the atmosphere as they grow. For this reason, widespread deforestation has contributed to rising atmospheric carbon dioxide levels. However, trees grow faster in higher concentrations of atmospheric carbon dioxide. Any reforestation efforts undertaken now, therefore, not only help to contain levels of atmospheric carbon dioxide, but actually benefit from the high carbon dioxide levels.
Which of the following, if true, most seriously weakens the argument?
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A.Worldwide, the amount of forest that is legally protected from deforestation is steadily increasing.
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B.The chief source of the rising levels of atmospheric carbon dioxide is the burning of fossil fuels.
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C.The weeds and shrubs that compete for space with tree seedlings respond more vigorously to increases in carbon dioxide than tree seedlings do.
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D.Typically, land that has been deforested and is not deliberately replanted will eventually become forested again, though this will take much longer than if systematic reforestation is practiced.
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E.A number of pollutants, whose concentrations in the air are increasing, tend to slow the rate at which trees
C显示答案
