关于“沙子的开采”的评注

Comment on the Problem:Exploit Sand

从评阅者的角度对求解这道题目中值得注意的问题作了阐述,指出了学生的解答中好的作法及不足之处。

The Comment on the problem are presented from the judge point of view. The excellent methods and defects in the answers are pointed out in this paper.