kōng qì / zhōng / kě rán / qì tǐ / nóng dù / guò / gāo / shí / yù huǒ / jí yì / bào zhà

空气中可燃气体浓度过高时，遇火极易爆炸。

When the concentration of flammable gas in the air is too high, it easily explodes in the presence of fire.