B2 火山a mountain with a large, circular hole at the top through which lava (= hot liquid rock) gases, steam, and dust are or have been forced out
an extinct/dormant volcano 死/休眠火山
an active volcano 活火山
Erupting volcanoes discharge massive quantities of dust into the stratosphere. 火山喷发导致大量灰尘进入大气平流层。