If the electric motor driving an air compressor fails to start, the cause may be a （）. ["leaking unloader","tripped circuit breaker","control line leak","defective pop valve"]
I have to be responsible（）my Shipowner. ["against","for","to","with"]
升高污水温度，有利于（）溶液电阻。 ["降低","升高","稳定","波动"]
机泵效率是指电机效率与注水泵效率（） ["之和","之差","之积","之商"]
COD装置降解COD时，供水压力约为（）Mpa。 ["0.2","0.5","1.0","1.5"]
记录电话有哪三种主要方法？
