It's constantly blowing off a stream of gas.

它不断的爆出气体流。

Philippine officials have raised the alert level for one of the country's most active volcanoes after superheated streams of gas, debris and rocks cascaded down its upper slope.

菲律宾官员提高了该国最活跃火山之一的警戒级别，此前过热的气体、碎片和岩石流沿着其上斜坡倾泻而下。