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
个人觉得问题主要集中在选项B和C 题目的结论是Clearly, using this test, doctors can largely avoid unnecessary removals of the appendix without, however, performing any fewer necessary ones than before C并不能说明这个结论 但是B确可以 举个例子 如果只做两例手术 如果用原来的方法则很有可能造成50%的甚至100%的误切除 而B可以保证误切除的概率是0
[此贴子已经被作者于2008-6-24 0:19:18编辑过] |