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送交者: 车五进二 2019月11月18日12:26:25 于 [灵机一动] 发送悄悄话 |
回 答: 俺西医外科半辈子,见癌症病人成千上万,未见一例中医治疗有效的 由 北美朋友 于 2019-11-18 08:56:13 |
The cross section of the paper makes a spiral, we can appoximate it to be many layers of circles. The inner most layer has a radius 1+4/600 while the outer most layer has a radius of 5, therefore the radii make a arithemetic sequence. |
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