åçåå¾ä¸º2.å®çå¨é¿åé¢ç§¯ä¸ç¸ç
å¨é¿=4Ïï¼é¿åº¦åä½ï¼
é¢ç§¯=4Ïï¼é¢ç§¯åä½ï¼
å®ä»¬çåä½ä¸ä¸æ ·ï¼æ以ä¸ç¸çã
æåï¼è¯·ãé纳çæ¡ãï¼æ¨çé纳æ¯æçé¢çå¨åï¼è°¢è°¢ã
追é®è°¢è°¢
追çä¸å®¢æ°ï¼ä½ æ¿æé纳æççæ¡åï¼è°¢è°¢ã