LSAT Section1-I-6

bigmouse

6. No senator spoke at the convention unless he or she was a Democrat. No Democrat both spoke at the convention and was a senator.
Which one of the following conclusions can be correctly drawn from the statements above?
(A) N one but senators spoke at the convention.
(B) No Democrat spoke at the convention.
(C) Only Democrats spoke at the convention.
(D) No senator spoke at the convention.
(E) Some Democrat senators spoke at the convention.
answer my choice:B

prince

No senator spoke at the convention unless he or she was a democrat
结论，属于民主党人士（包括民主党兼议员和民主党）可以在会上发言。仅仅是议员不能发言。
民主党人士（包括民主党兼议员和民主党），所以不仅是民主党兼议员，也有可能只是民主党人士。只要属于民主党 都可以发言）
No democrat both spoke at the convention and be was a senator
结论，民主党中的议员不能发言，仅仅是民主党人士可以发言。因为答案3有歧义，忽略了民主党人士兼议员人士。
根据1-2结论推出， 议员不能发言。
这是我一个同事给我的解释，英语专业，非常明了，


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上面是我从网上下的，可以参考。下面是我自己的解释
(A) N one but senators spoke at the convention.(此题目中没有排除其它人在这里演讲)
(B) No Democrat spoke at the convention（与第一句话矛盾）.
(C) Only Democrats spoke at the convention（此题目中没有排除其它人在这里演讲）.
(D) No senator spoke at the convention。（正确，用反证话。假如有senator演讲，根据：根据第一话得出他是Democrat。因此得出他是Democrat同时又在演讲。与最后一句话矛盾。See?）.
(E) Some Democrat senators spoke at the convention。（与推论无关）

bigmouse

呵呵，谢谢你的细心讲解！