£¨1£©ÒÑÖª¼¯ºÏM£½ £¬N£½ £¬Ôò £½
£¨A£©£¨£­4,1£Ý¡¡¡¡£¨B£©£Û1,4£Ý¡¡¡¡£¨C£©£Û£­6,£­4£©¡¡¡¡£¨D£©£Û£­6,4£©
£¨2£©ÒÑÖª¸´Êý £¬Ôò¸´ÊýzµÄÄ££üz£ü£½
£¨A£© ¡¡¡¡£¨B£© ¡¡¡¡£¨C£© ¡¡¡¡£¨D£©
£¨3£©“ ”ÊÇ“ £­4£¾0”µÄ
£¨A£©