跪求2006年美国MCM数学建模的【试题】和【答案】

我找到了一个网站，你看看有没有你要的东西。

http://mcm.ustc.edu.cn/wangjie.htm

这好象很难找哦！
我都找了几天了，实在是找不到，抱歉！
呵呵！等以后在找了~~

A: Positioning and Moving Sprinkler Systems for Irrigation
There are a wide variety of techniques available for irrigating a field. The technologies range from advanced drip systems to periodic flooding. One of the systems that is used on smaller ranches is the use of “hand move” irrigation systems. Lightweight aluminum pipes with sprinkler heads are put in place across fields, and they are moved by hand at periodic intervals to insure that the whole field receives an adequate amount of water. This type of irrigation system is cheaper and easier to maintain than other systems. It is also flexible, allowing for use on a wide variety of fields and crops. The disadvantage is that it requires a great deal of time and effort to move and set up the equipment at regular