在屏幕上画一个钟，时钟显示的时间和系统时间相同。钟的面板上有时针、分针、秒针3个表针在走动。随着秒钟的走动不断发出嘀嗒声。相关函数：sound(),gettime()等。 -On the screen to draw a clock, the clock shows the time and the same system time. The panel has bell clock, minute hand, second hand in the three hands move arou