主要排水设备中备用水泵的能力应不小于工作水泵能力的（）
A、70%
B、60%
C、50%
参考答案：A
________ of being involved in the attempted murder, she was questioned by the police.[ ]
A．Convinced
B．Suspected
C．Charged
D．Confirmed
纯铜有哪些性能？用途是什么？
