The quality of EGC messages is（）affected by the position of the ship, the time of reception and climatic conditions. ["sometimes","all times","never","partly"]
预应力钢筋包括哪些？
门诊日志的主要内容有哪些？
装运货物使用掩块可以在底座上滑动（）。 ["80mm","90mm","100mm","110mm"]
哪些介质管道须静电接地？管网的接地连接点和接地电阻值有何要求？
采用打桩法人工地基时，应注意局部换土的新土应与周围土质接近，为什么？
