Warning: Undefined array key 1 in D:\INETPUB\VHOSTS\luhui.net\httpdocs\en\index.php on line 138 一次方程 【计】 first-order equation\n【经】 linear equation - 鲁虺汉英词典 Warning: Undefined array key 1 in D:\INETPUB\VHOSTS\luhui.net\httpdocs\en\index.php on line 220