This is called coal bed methane. Why is this picture interesting? Because if coal turns out to be concentrated plant life, the reason why you may get a differential in gas output between one mine and another -- the reason why one mine may blow up and another one may not blow up -- may be because there's stuff eating that stuff and producing gas.
这种气体称为煤层甲烷气。为什么 这个画面很有趣？因为如果煤炭真的是 浓缩的植物体，那么你在 不同的煤矿发现有不同的气体 有的煤矿会爆炸 而有的又不会，可能都是因为 有些东西吃掉了另一些东西而产生气体。