构建vi，每秒显示0~1之间的随机数。与此同时，计算并显示最后产生的4个随机数的平均值。只有4个数后才显示平均值，否则显示0。每次随机数大于0.5时，使用beep.vi产生蜂鸣器-Build vi displayed per second random number between 0 and 1. Meanwhile, calculates and displays the average of the last four random numbers generated. After only 4 numbers show the average, otherwise 0. Each random number is greater than 0.5, use beep.vi generate buzzer