求助一道逻辑题，被搞晕了，大家帮忙看看

wdpywhys

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 conclusion can be correctly drawn from the statement above?
A. No 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

zowenny

senator spoke可以推出它是D
如果它是D可推出它不会both speak and 是Senator
senator spoke 推出 不会both speak and 是Senator 这个推理有矛盾啊 换句话说就是没有Senator 在会上spoke了

gtr

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 conclusion can be correctly drawn from the statement above?
A. No 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

-- by 会员 wdpywhys (2010/2/7 15:47:54)

我们把情况都列出来：
1。 democrat senate （不能speak) 2。 non-democrat senate （不能speak) 3。democrat non-senate （能speak)4。non-democrat non-senate （能speak)
结果就是senate都不能speak, 不管是不是democrat

dontwannalose

whatz the source of this question?

mycontrol01

赞成 2,3L

俺只选的出答案 分析没这么细..