说明：  流水线作业练习，A、B机器处理作业1～5所需要的时间分别是『。。。。』『。。。。』，一台机器一次只能处理一个作业，一个作业只能由一台机器完成，求A、B完成所有作业的最短时间。
(pipeline workbook, A, B machines handling a ~ 5 respectively, the time required is . . . . ]. . . . And one machine can handle only one time operation, an operation only by the completion of a machine, for A, B complete all work is the shortest time.)