难易程度:★★★★★
题目题材:工业
gre argument 71题目:
Copper occurs in nature mixed with other minerals and valuable metals in ore, and the proportion of copper in the ore can vary considerably. Until fairly recently, the only way to extract pure copper from ore was by using a process that requires large amounts of electric energy, especially if the proportion of copper in the ore is low. New copper-extracting technologies can use up to 40 percent less electricity(3) than the older method to process the same amount of raw ore, especially when the proportion of copper in the ore is high(1,2). Therefore, we can expect the amount of electricity used by the copper-extraction industry to decline significantly (4, 5, and 6).
提纲:
(1)The author fails to provide information regarding the efficiency of the new method when the proportion of copper in the ore is low.
(2)The author fails to inform us about the fraction of ore in which the proportion of copper in the ore is low.
(3)The author fails to consider other expenditures of the new technology.
(4)There may be some obstacles in the application of the new technology, thus the new method might not be practically feasible at current stage.
(5)We need to know what fraction of copper companies would be interested in the new technology, or are capable of using the new method.
(6)The author fails to consider other factors that will lead to the increase in the amount of electricity used by the copper-extraction industry.
注:题目中括号里的数字表明这句话体现的是提纲中第几号缺陷。
无论是gre issue还是gre argument,考生都应该养成写提纲的习惯。这种提纲式的gre写作练习可以帮助考生锻炼写作的逻辑性,而gre写作高分最重要的得分依据就是作文的逻辑性要强。