程序能够画圆、正弦曲线和椭圆，画笔的颜色和风格可调，颜色有红、绿、蓝三种，画笔风格有实线、点线和虚线。该程序主要反映画图类的调用和指针的运用。-Procedures drawcircle, sinusoid and elliptical, brushes adjustable color and style, color, red, green, blue, brushes have a solid line style, point line and the dotted line. The