65

　　意;使用other将market for paper排除在外,表达出market for paper和other market的对比关系

　　(C)第一个it指代模糊,既可能指代paper production又可能指代use of wood,如果根据优先原则指代use of wood则不符合逻辑;第二个it错误同A选项

　　(D) its的指代错误同C的第一个it; all后面应该加other将它自身排除在外才能表达两者间的对比关系

　　(E) its错误同D选项; it错误同A选项

　　12. Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.

　　(A) while at the same time they have introduced some 100,000 dangerous chemical pollutants, having

　　(B) while at the same time introducing some 100,000 dangerous chemical pollutants that have

　　(C) while they have introduced some 100,000 dangerous chemical pollutants at the same time, which have

　　(D) but introducing some 100,000 dangerous chemical pollutants at the same time that have

　　(E) but at the same time introducing some 100,000 dangerous chemical pollutants, having

　　(A)第二个they有指代不清的嫌疑,既可能指代第一个they所指代的Industrialization and modern methods of insect control又可以指代chemical pollutants;句尾的分词结构having gone…目的是作pollutants的后置定语，但有作状语的歧义存在。

　　(B)正确,使用sb do… while doing结构, 省掉了they, 避免了同第二个they产生指代不清的嫌疑;使用限定性定语从句符合逻辑意思

　　(C)使用which作非限定定语从句,导致逻辑错误,表明所有的chemical pollutants都 have gone virtually unregulated; 第二个they有指代不清的嫌疑

　　(D) but introducing不能和have improved构成并列

　　(E) but… introducing不能和have improved构成并列; 句尾的分词结构having gone…目的是作pollutants的后置定语，但有作状语的歧义存在。

　　13. Officials at the United States Mint believe that the Sacagawea dollar coin will be used more as a substitute for four quarters rather than for the dollar bill because its weight, only 8.1 grams, is far less than four quarters, which weigh 5.67 grams each.

　　(A) more as a substitute for four quarters rather than for the dollar bill because its weight, only 8.1 grams, is far less than

　　(B) more as a substitute for four quarters than the dollar bill because it weighs only 8.1 grams, far lighter than

　　(C) as a substitute for four quarters more than for the dollar bill because it weighs only 8.1 grams, far less than

　　(D) as a substitute for four quarters more than the dollar bill because its weight of only 8.1 grams is far lighter than it is for

　　(E) as a substitute more for four quarters rather than for the dollar bill because its weight, only 8.1 grams, is far less than it is for

　　(A) more… rather than搭配错;its weitht 和后面 four quarters 比较对象不对等。