在缓冲区中预放了一些字母,运行时,可按照屏幕上显示的字母进行输入练习,每输入完一行按回车键后,可显示出练习输入的时间（可以用系统时间计时）-Pre-amplifier in the buffer zone in a number of letters, run-time can be displayed on the screen in accordance with the input letters to practice, each finished entering his press