110kV及以下变配电所监控系统可以采用( )。
A．双环网
B．单环网
C．双网
D．单网
参考答案：D
I _____ you would come today. You _____ me a phone call in advance.
A．don’t expect; should have given
B．didn’t expect; could have given
C．hadn’t expected; ought to give
D．didn’t expect; can have given
这一生产企业从B厂购进设备的净成本为( )元。
A．18754.72
B．18867.92
C．21004.27
D．21367.52
I _____ you would come today. You _____ me a phone call in advance.