PLC的输出继电器Y是PLC用于将输出信号传给外部负载。()
参考答案:对
—It’s reported that the new underground line has been completed.
—Yes but it hasn’t been made clear _____it’s to be opened to traffic.
A.that
B.who
C.what
D.when
FQX-25∕100QH型绝缘子的绝缘部分长度不小于()。
A.500mm
B.600mm
C.700mm
D.800mm