圣海伦斯火山 Mount St Helen's，US 参考资料：http://baike.baidu.com/view/57339.html?wtp=tt
Thebillow of steam(翻滚的蒸汽) rose from an area where a large upwelling orbulge4of rock has been growing onthedome5-shaped formation of rock in the crater(火山口的圆顶状岩石). The plume rose several hundred feet above the 8,364-foot volcano, and light wind slowly blew it toward the s...