正转和反转程序处于同一个状态图中,最好有以下处理()
A. 急停
B. 起保停
C. 软件互锁
D. 硬件互锁
查看答案
适合做单流程的程序,一般具有以下特性( )
A. 就是一个复杂的状态
B. 就是一个程序
C. 就能够将这个程序分解成很多不同的工序
D. 就能按照时间或者工序顺序连接
单流程不允许返回到初始状态()
A. 对
B. 错
I have lived here ________at least twenty years.
A. for
B. since
I _____ to take a good holiday this year, but I wasn't able to get away.
A. hope
B. have hoped
C. had hoped
D. hoped