gas works coal tar煤气焦油
gas of coal mine煤矿瓦斯
gas house coal tar煤气焦油沥清
gas outburst coal瓦斯突出煤体
Gas from coal煤型气
gas from coal measures的翻译是气体从煤措施;煤系地层气
gas-coal technology气化技术
gas s coal气煤
gas of coal bed煤层瓦斯
N（名词） coal that is rich in volatile hydrocarbons, making it a suitable source of domestic gas 烟煤