goaf [goʊf]

例句:

• And above 90 % spontaneous combustion occurs in goaf.
  其中90%以上自然发火发生在采空区.
  
• The coal spontaneous combustion in the goaf is one of the main coal disasters.
  采空区煤炭自燃火灾一直是我国煤矿的主要灾害之一.
  
• The method of gas drainagecoal seam gas drainage , near coal gas drainage , and goaf gas drainage.
  瓦斯抽放的方法有本煤层抽放 、 邻近层抽放和采空区抽放.