我们都曾听说过：世界上没有完全相同的两片雪花。这一概念更具诗情画意，而不是科学道理，不过它也点出了关键：大自然既具有多样性，也有其精确性--雪花的几何形状就是大自然运动的结果，不过很多时候不可预料，而是遵从于物理学和数学的基本原理。 .pb{} .pb textarea{font-size:14px; margin:10px; font-family:"宋体"; background:#FFFFEE; color:#000066} .pb_t{line-height:30px; font-size:14px; color:#000; text-align:center;} /* 分页 */ .pagebox{overflow:hidden; zoom:1; font-size:12px; font-family:"宋体",sans-serif;} .pagebox span{float:left; margin-right:2px; overflow:hidden; text-align:center; background:#fff;} .pagebox span a{display:block; overflow:hidden; zoom:1; _float:left;} .pagebox span.pagebox_pre_nolink{border:1px #ddd solid; width:53px; height:21px; line-height:21px; text-align:center; color:#999; cursor:default;} .pagebox span.pagebox_pre{color:#3568b9; height:23px;} .pagebox span.pagebox_pre a,.pagebox span.pagebox_pre a:visited,.pagebox span.pagebox_next a,.pagebox span.pagebox_next a:visited{border:1px #9aafe5 solid; color:#3568b9; text-decoration:none; text-align:center; width:53px; cursor:pointer; height:21px; line-height:21px;} .pagebox span.pagebox_pre a:hover,.pagebox span.pagebox_pre a:active,.pagebox span.pagebox_next a:hover,.pagebox span.pagebox_next a:active{color:#363636; border:1px #2e6ab1 solid;} .pagebox span.pagebox_num_nonce{padding:0 8px; height:23px; line-height:23px; color:#fff; cursor:default; background:#296cb3; font-weight:bold;} .pagebox span.pagebox_num{color:#3568b9; height:23px;} .pagebox span.pagebox_num a,.pagebox span.pagebox_num a:visited{border:1px #9aafe5 solid; color:#3568b9; text-decoration:none; padding:0 8px; cursor:pointer; height:21px; line-height:21px;} .pagebox span.pagebox_num a:hover,.pagebox span.pagebox_num a:active{border:1px #2e6ab1 solid;color:#363636;} .pagebox span.pagebox_num_ellipsis{color:#393733; width:22px; background:none; line-height:23px;} .pagebox span.pagebox_next_nolink{border:1px #ddd solid; width:53px; height:21px; line-height:21px; text-align:center; color:#999; cursor:default;}