各位牛人，跪求两道逻辑题解释，非常感谢！！！

iamdurant

1.    rintwell's Ink Jet Division manufactures ink-jet printers and the ink cartridges they use. Sales of its ink-jet printers have increased. Monthly revenues from those sales, however, have not increased, because competition has forced Printwell to cut the prices of its printers. Unfortunately, Printwell has been unable to bring down the cost of manufacturing a printer. Thus, despite the increase in printer sales, the Ink Jet Division must be providing the company with much smaller than it used to.

              Which of the following, if true, most seriously weakens the argument?
            A. Ink-jet printers in regular use frequently need new ink cartridges, and Printwell's printers only accept Printwell's ink cartridges.
            B. Unlike some competing companies,Printwell sells all of its printers through retailers, and these retailers' costs account for a sizable proportion of the printers' ultimate retail price.
            C. Some printer manufactureres have been forced to reduce the sale price of their ink-jet printers even more than Printwell has.
            D. In the past yedar, no competing manufacturer of ink-jet printers has had as great an increase in unit sales of printers as Printwell has.
            E. In the past year, sales of Printwell's ink-jet printers have increased more than sales of any other type of printer made by Printwell.
              上面这题答案是A, 个人选的是C，完全无法理解，求大神帮助，谢谢


           2   Of patients over 65 years old who survived coronary bypass surgery-- a procedure widely prescribed for people with heart disease--only 75% benefited from the surgery. Thus it appears that for one in four such patients, the docors who advised them to undergo this surgery, with its attendant risks and expense, were more interested in an opportunity to practice their skills and in their fee than in helping the patient.

                Which of the following, if true, most seriously undermines the argument?
             A. Many of the patients who receive coronary bypass surgery are less than 55 years old.
             B. Possible benefits of coronary bypass surgery include both relief from toubling symptoms and prolongation of life.
             C. Most of the patients in the survey decided to undergo coronary bypass surgery because they were advised that the surgery would reduce their risk of future heart attacks.
             D. The patients over 65 years old who did not benefit from the coronary bypass surgery were as fully informed as those who did benefit from the surgery as to the risks of the surgery prior to undergoing it.
             E. The patients who underwent coronary bypass surgery but who did not benefit from it were medically indistinguishable, prior to their surgery, from the patients who did benefit.
              上面这题答案是E, 我选的是D,一直困惑于这两题，谢各位高手帮助！！

超人力霸王

fully informed 和 more interested in....没有逻辑上的必然。

浮生若梦

顶一个

iamdurant

现在完全明白了！！非常感谢！！

camelo777

第二题确实有难度，我第一次做的时候也选了D，D错就错在，虽然是fully informed ，但是医生仍然可以挑那些本来身体就不太好，不太可能手术成功的来做，起不到削弱的作用，相反，E的话，说在做手术前所有患者是medically indistinguishable，也就是说医生是区分不出来谁能治好谁不能的，所以也就削弱了原文的结论

iamdurant

顿悟！！非常感谢！！

camelo777

第一题，题目说Printwell’s Ink Jet Division manufactures ink-jet printers and the ink cartridges，可以记为A和B，也就是说这个公司生产A和B这两种东西，然后题目接着说A的sales增加了，但是收益却没有增加，因为竞争使得这个公司降低了价格，最后说因为这个公司不能减少制作A的成本，所以这个Ink Jet Division 给公司带来的收益比以前少了。

问题问削弱，首先注意到，题目一直在说因为Ink Jet Division 的A价格低了，成本降不了，所以虽然sale高，但是收入却没有增加，看到这我们很快发现了文章一个错误，那就是B呢？Ink Jet Division 不光只卖A 啊，它也卖B啊，所以这就是削弱的切入点

A选项说  A这个东西需要经常换ink也就是B，而A只能用B这种ink，别的不行，由此可以看出，A的sale增加，虽然没有带来直接的收益，但是带动了B的增加，因此不能说这整个Ink Jet Division 给公司带来的收益比以前少了，因此是削弱。

iamdurant

第二题，我选D，因为我觉得如果说收益的人和没有收益的人都得到了医生的充分通知(Informed)的话，说明医生是出于为病人考虑，那么就可以削弱医生建议病人做手术是为了自己提高技术和手术费的结论了。请高手指教