（1）要求利用面向对象的方法以及C++的编程思想来完成系统的设计；



（2）要求在设计的过程中，建立清晰的类层次；



（3）在系统中至少要定义三个类，每个类中要有各自的属性和方法；



（4）在系统的设计中，至少要用到面向对象的一种机制。

-(1) require the use of object-oriented method and C++ of programming ideas to complete the design of the system　(2) The requirements in the design process, the establishment of a clear class hierarchy　(3) in the system you want to define at least three classes, have their own properties and methods of each class　(4) In the design of the system, at least to use the object-oriented mechanism.