（1）　　编写一个代表圆柱体的Cylinder类，该类是Circle类的子类。Cylinder类包括圆柱体的高度变量height、计算圆柱体的体积方法volume()和计算表面积的方法surfaceArea()。

（2）　　编写测试Cylinder类的CylinderTest类，并在该类得main方法中调用Cylinder类的相关方法。

（3）　　程序调试通过后填写实验报告。

-( 1) the preparation of a representative cylinder Cylinder class, the class is a subclass of Circle. The Cylinder includes cylinder is highly variable height, calculation of cylinder volume method ( volume ) and the calculation method of surface area ( surfaceArea ).( 2) writing a test class Cylinder class CylinderTest, and the main method called Cylinder correlation method.( 3) through debugging procedures after completing the experiment report.