编写程序，创建类MyMath，计算圆的周长和面积以及球的表面积和体积，并编写测试代码，结果均保留两位小数

class MyMath:
def __init__(self, radius):
self.radius = radius

def circle_circumference(self):
circumference = 2 * 3.14 * self.radius
return round(circumference, 2)

def circle_area(self):
area = 3.14 * self.radius ** 2
return round(area, 2)

def sphere_surface_area(self):
surface_area = 4 * 3.14 * self.radius ** 2
return round(surface_area, 2)

def sphere_volume(self):
volume = 4 / 3 * 3.14 * self.radius ** 3
return round(volume, 2)

# 测试代码
radius = float(input("请输入圆的半径："))
my_math = MyMath(radius)
print("圆的周长为：", my_math.circle_circumference())
print("圆的面积为：", my_math.circle_area())
print("球的表面积为：", my_math.sphere_surface_area())
print("球的体积为：", my_math.sphere_volume())