说明： 点击开始按扭时，程序启动，小球会向外旋。点击退出按扭时，会结束程序。点击加球按扭时，球的个数会加1。点击减球按扭时，球的个数会减1。 (Click on the buttons at the beginning of the commencement of proceedings, and the ball will spin out. Click on the buttons to withdraw from, will end the proceedings. Click on the buttons plus the ball, the ball will increase the number one. Click on the buttons by the ball, the ball will be reduced by a number.)
