Guillemots are birds of Arctic regions. They feed on fish that gather beneath thin sheets of floating ice, and they nest on nearby land. Guillemots need 80 consecutive snow-free days in a year to raise their chicks, so until average temperatures in the Arctic began to rise recently, the guillemots' range was limited to the southernmost Arctic coast. Therefore, if the warming continues, the guillemots' range will probably be enlarged by being extended northward along the coast.
Which of the following, if true, most seriously weakens the argument?
Guillemots are birds of Arctic regions. They feed on fish that gather beneath thin sheets of floating ice, and they nest on nearby land. Guillemots need 80 consecutive snow-free days in a year to raise their chicks, so until average temperatures in the Arctic began to rise recently, the guillemots' range was limited to the southernmost Arctic coast. Therefore, if the warming continues, the guillemots' range will probably be enlarged by being extended northward along the coast.
Which of the following, if true, most seriously weakens the argument?
A Even if the warming trend continues, there will still be years in which guillemot chicks are killed by an unusually early snow. 分析A选项
B If the Arctic warming continues, guillemots' current predators are likely to succeed in extending their own range farther north. 分析B选项
C Guillemots nest in coastal areas, where temperatures are generally higher than in inland areas. 分析C选项
D If the Arctic warming continues, much of the thin ice in the southern Arctic will disappear. 分析D选项
E The fish that guillemots eat are currently preyed on by a wider variety of predators in the southernmost Arctic regions than they are farther north. 分析E选项
结论:the guillemots' range will probably be enlarged by being extended northward along the coast
这句话可以攻击的点有两处:
第一种削弱方向:the guillemots' range will NOT probably be enlarged by being extended northward along the coast第二种削弱方向:the guillemots' range will probably be enlarged by NOT being extended northward along the coast
而题中给了我们大量的无用信息来达成distraction:所有的需要连续80天下雪等等都是无用信息。目的都是通过把你绕进去来Hide the correct answer。
D的逻辑很简单,随着温度增加北极南部的冰会融化--->the guillemots' range will probably NOT be enlarged by being extended northward along the coast, but rather shift northward along the coast
不是把底盘扩大,而是向北移动(因为南边的冰融了不满足其生存的必要条件)