不解啊不解！DS题，如问X+Y>0?，怎么算sufficient？

1.       x<0, y>0, x+y>0？

(1) 0到-y的距离小于0到x的距离
            

(2)0到y的距离小于0到x的距离

(1) MingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">得到xMingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">絕對值大於yMingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">，又x<0MingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">且y>0MingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">，故x+y<0  sufficient
(2) MingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">同(1)xMingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">絕對值大於yMingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">，又x<0MingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">且y>0MingLiU","serif"; mso-bidi-font-size: 9.0pt; mso-bidi-font-family: Tahoma; mso-ascii-font-family: Georgia; mso-hansi-font-family: Georgia; mso-themecolor: accent1; mso-themeshade: 128;">，故x+y<0 sufficient

选
        D

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某道JJ题

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我总认为题目问，比如在这道题中，X+Y>0？

只有在能通过(1）或者（2）得到X+Y>0才算sufficient，若<0就不sufficient

那么应该选E

我一直都这样理解：

题目并不是问你能否通过给出的条件得到 x＋y是否大于0或者小于0，而是问条件是否sufficient to得到答案x+y>0

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马上就要考了

这点还是搞不明白