煤矿中天然存有高爆气体。Highly explosive gas is naturally found in coal mines.许多人到煤矿来,是因为契约规定必须服务几年.Many people came to the coal mineindentured for several years.煤矿工人须在地下工作.Coal miners have to work under the ground....
从描记中可以看出, 这里的通讯信号不太稳定.From the linear graph, the communication signal is not stable here.用肌动电流描记器来诊断神经肌肉的无序状态.The application of faradic current to stimulate muscles and nerves.描记心外膜电图,计算心肌缺血程度.The epicardial electrogram...