1991年是个十分难得的左右对称年——19—91。从第十一世纪到二十世纪的一千年中,对称的年份只有十个,即:1001,1111,1221,1331,1441,1551,1661,1771,1881,1991。也就是说,一个世纪只有—个对称年。两个对称年之间,一般长达110年。所以,一个人如果能活满一百一十岁,肯定可以遇到一个对称年。生年巧,寿命虽短也能遇到对称年。反之如果出生和死亡在两个对称年之间,即使长命百岁,也不可能遇到对称年。只有二十世纪与二十一世纪的对称年相隔最近,仅11年,即1991与2002。所以,现在活着的人只要能 1991 is a very rare year of symmetry - 19-91. From the eleventh to the twentieth centuries, there were only ten years of symmetry, namely: 1001,1111,1221,1331,1441,1551,1661,1771,1881,1991. In other words, there is only one symmetrical year in a century. Between two symmetrical years, generally up to 110 years. Therefore, if a person can live a full hundred years of age, he can definitely encounter a symmetrical year. Happy life, life is short but also encounter symmetrical years. Conversely, if birth and death are between two symmetry years, even if they live a long life, they can not encounter symmetrical years. Only the Symmetry years of the twentieth and twenty-first centuries are the closest, only 11 years, 1991 and 2002. So, as long as people can live