用74ls164的并行输出端接8个发光二极管，利用它的串入并出的功能，把发光二极管从左到右轮流点亮一个灯，并反复循环。（即流水灯效果）(A parallel output terminal of 74LS164 is used to connect 8 light-emitting diodes. By using its function of string in and out, the LED can turn a lamp on from left to right and circulate repeatedly. (that is, water lamp effect))