2选1数据选择器。它的功能是如果S=0则Y=A 如果S=1则Y=B-2 election 1 data selector. Its function is that if S = 0 is Y = A if S = 1 is Y = B

经典的B/S框架结构练习代码，适合初学者。 ——在线小说阅读器。-The classic structure of B/S framework the exercises code, suitable for beginners.- Online fiction reader.