说明：  双四选一数据选择器74LS153,1、写一个程序，用顺序描述语句和并发描述语句（选择信号代入语句或者条件信号代入语句）分别控制74LS153的一个输出端Q。 2、比较一下顺序语句与并行语句各自的优缺点。 输入：逻辑开关。输出：LED灯。
(A double four election data selector 74LS153, 1, write a program, with sequential and concurrent statements describe the statement describes (select signal incorporated into the conditions of signal substitution statement or statements) are a control 74LS153 output Q. 2, compare the sequence of statements and their respective advantages and disadvantages of the parallel statement. Input: logic switch. Output: LED lights.)