第3个回答 2011-06-08
1/2......1/60;2/3,2/5,2/7,2/9.....2/59;3/4,3/5,3/7,3/8......3/58,3/59;4/5,4/7......4/59;5/6,5/7,5/8,5/9......5/56,5/57,5/58,5/59;6/7,6/11,6/13,6/17,6/19,6/23,6/25,6/29,6/31,6/35,6/37,6/41,6/43,6/47,6/49,6/53,6/55,6/59。共216个
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