A smouldering cigarette can kindle a devastating bushfire.闷燃著的香烟会引起毁灭性的林区大火。The bushfire actually helped to burn off a lot of dead undergrowth.森林大火实际上有助于烧掉很多枯死的矮树丛。The bushfire actually helped to burn off a lot of dead undergrowth.林区大火实际上有助于清除很多枯死的矮灌木。