民航系统功能：能给客户提供订票、退票的功能，还能浏览航班航线信息（如航班号、航线、飞行时间及成员订额）和查询航班信息-CAD system functions : give customers booking, a refund of the function, can browse flight route information (such as flight number, route, time of flight and members of the amount set), and

在cad中统计工程量,将字符转换为数字，然后相加，使工作效率提高。-add the number in autocad,and it will make you short down your work in the daily life,and make you work fastly.

查空缺或多余的杆件号(ch普通梁和chpgl组合梁) CAD lisp-Check the vacancy or the redundant rod number (CH ordinary beam and chpgl composite beam) CAD lisp