说明：  1) 从屏幕上方以一定的时间间隔随机落下可显示字符，字符的出现位置亦是随机的； 2) 在多个字符（可以简化为仅有一个字符）下落的过程中可输入任意键，若键入与其中的任意一个字符相匹配的键，则该字符高亮显示并发出蜂鸣声，同时计分； 3) 按ESC键结束练习并显示命中率； 4) 再次按ESC键退出。 2. 硬件和软件环境： 个人PC机，WINXP操作系统，MASM5.0编程环境
(1) from the top of the screen in a certain time interval sets can show that the random characters The characters also appeared location is random; 2) in a number of characters (which can be simplified to only one character) the whereabouts of the process to be imported Anykey. If the type and the arbitrary character of the keys match, then the characters highlighter and issued faint buzzing sound while scoreboard; 3) by the end of the ESC key exercises and show hit rates; 4) again by the ESC key exit. 2. The hardware and software environment : the individual PC, WINXP operating systems, programming environment MASM5.0)