A.四类四种 B.四类五种 C.四类六种 D.四类七种
A.电气火灾 B.触电伤害 C.线路过载 D.开关跳闸
A.1 B.2 C.3 D.4
A.水平3m/垂直4m B.水平6m/垂直4m C.水平5m/垂直3m D.水平3m/垂直6m