GWD21-Q4，看了讨论还是晕

Appendicitis (inflammation of the appendix) is potentially fatal; consequently, patients with symptoms strongly suggesting appendicitis almost always have their appendix removed.  The appropriate surgery is low-risk but performed unnecessarily in about 20 percent of all cases.  A newly developed internal scan for appendicitis is highly accurate, producing two misdiagnoses for every 98 correct diagnoses.  Clearly, using this test, doctors can largely avoid unnecessary removals of the appendix without, however, performing any fewer necessary ones than before, since ______.

A.      the patients who are correctly diagnosed with this test as not having appendicitis invariably have medical conditions that are much less serious than appendicitis

B.       the misdiagnoses produced by this test are always instances of attributing appendicitis to someone who does not, in fact, have it

C.      all of the patients who are diagnosed with this test as having appendicitis do, in fact, have appendicitis

D.      every patient who is diagnosed with this test as having appendicitis has more than one of the symptoms generally associated with appendicitis

E.       the only patients who are misdiagnosed using this test are patients who lack one or more of the symptoms that are generally associated with appendicitis

1）看了讨论还是晕，最后句however后面想表达什么？比过去有较少的有必要的手术？

2）C仅仅说了手术的都是有必要的，但被误诊的是不是需要手术没有说明，是不是就是这里出了问题？

3）B说误诊的那些人被诊断没有阑尾炎而事实上是有的？是不是这个意思，还是题干最后句话没懂他想表达什么意思

请教大家啦

Clearly, using this test, doctors can largely avoid unnecessary removals of the appendix without, however, performing any fewer necessary ones than before

你可以把however提到此句首，因为整个句子都是对上一句的转折，此句的关键点就变成了doctors can largely avoid unnecessary removals of the appendix without performing any fewer necessary ones than before

A。说的是患病与不患病的那个的medical conditions 严重，与原文无交点。

B。text的误诊是——将阑尾炎这个病加之于那些没有患病的人身上——的情况。这个也无关啊。如果， 你要说它对，那它就没有C直接。

D。E。说的是症状的有无或多少的问题，与原文、特别是原文的结论无关。

個人的理解......參考看看

4. GWD21-Q4:

Which of the following most logically completes the passage?

Appendicitis (inflammation of the appendix) is potentially fatal; consequently, patients with symptoms strongly suggesting appendicitis almost always have their appendix removed.  The appropriate surgery is low-risk but performed unnecessarily in about 20 percent of all cases.  A newly developed internal scan for appendicitis is highly accurate, producing two misdiagnoses for every 98 correct diagnoses.  Clearly, using this test, doctors can largely avoid unnecessary removals of the appendix without, however, performing any fewer necessary ones than before, since ______. 前提：使用新技术不会使必要动的手术量减少同时也会避免动不必要的手术　　　predict：正确面：新的技术都能够正确诊测出真的有患病的　or错误面：新的技术中的2%的误诊都是那些说病人有得病但其实没有的

A.    the patients who are correctly diagnosed with this test as not having appendicitis invariably have medical conditions that are much less serious than appendicitis　serious的程度无关

B.    the misdiagnoses produced by this test are always instances of attributing appendicitis to someone who does not, in fact, have it　命中预测

C.    all of the patients who are diagnosed with this test as having appendicitis do, in fact, have appendicitis　竟然也是预测中的，想一下，从正面说原因不如从反面说原因好，再看一下题目的前提是说使用新技术「不会」使必要动的手术量减少，试想一下如果新技术误诊的那2%里面都是那些实际上有却被说没有的，那么新技术就会使必要动的手术量减少，所以这个选项没有比B好

D.    every patient who is diagnosed with this test as having appendicitis has more than one of the symptoms generally associated with appendicitis　有多少symptoms无关

E.     the only patients who are misdiagnosed using this test are patients who lack one or more of the symptoms that are generally associated with appendicitis　缺少多少symptoms无关

大致意思

阑尾炎的解决方案就是手术切除。虽然风险很低，但是有20%没有必要。

新的内窥镜技术能够准确诊断，98%诊断正确，另有2%诊断错误。

然而，显然，与以前相比，使用这项技术不会使得医生少做任何该做的手术就能够很大程度上避免不必要的切除

因为(B)，这项技术误诊的例子总是诊断某人没有得阑尾炎，但是他实际上得了。

换言之：只要这个测试诊断错误，就是医生该做手术的情况，支持结论没有漏掉任何该做的手术。

怎么这么郁闷？标答不是B吗，怎么是C呢？怎么答案版本都不一样了

doctors can largely avoid unnecessary removals of the appendix 医生可以大大地减少不必要的阑尾切除手术

performing any fewer necessary ones than before 比以前做更少看上去有必要的手术，

假设以前50个人做了手术，事实上只有40个人有必要做

而如果是在新的技术下会把有病的当成没病的，也就是说认为有必要做手术的人还要少，比如说39要做的（因为40*2%不太方便取整），

那么也就说减少不必要的手术不是通过增加检测病的正确率，

而是由于这种测试特殊的误诊，把没病的堪称有病的，才减少有必要的手术的