A.低壓管網(wǎng)B.中壓管網(wǎng)C.次高壓管網(wǎng)D.高壓管網(wǎng)
A.5B.6C.7D.8
A.可燃物、氧氣、點(diǎn)火源 B.可燃物、助燃物、明火 C.可燃物、助燃物、點(diǎn)火源