pNa值
桥式起重机故障中,属于大车运行机构故障的有:()。 ["A、桥架歪斜运行、啃轨","B、个别滑轮不转动","C、小车三条腿运行","D、减速器整体发热","E、制动器不松闸","F、定子局部过热","G、电动机在工作时振动","H、交流电磁铁工作时声响大","I、控制器合上后电动机不转","J、起重机运行中经常掉闸"]
变压器在电路中主要作用是() ["A、分压","B、分流","C、变换阻抗"]
下面()是通过离子键作用形成的。 ["A、NACL","B、氧分子","C、氯分子","D、氢分子"]
QC小组的注册登记()进行一次。 ["每年","每2年","每3年","不定期"]
羊绒的好处?