[img]http://hiphotos.baidu.com/%CB%BF%BD%ED%B2%BC%C3%C0/pic/item/fc33d125397bc406d40742d3.jpg[/img]

[img]http://hiphotos.baidu.com/%CB%BF%BD%ED%B2%BC%C3%C0/pic/item/db1377c2d5525978b319a8dc.jpg[/img]

[img]http://hiphotos.baidu.com/%CB%BF%BD%ED%B2%BC%C3%C0/pic/item/4223c594de1851257bf480dc.jpg[/img]
麻烦各位前辈 帮忙解决一下这个作业题 小弟感激不尽