According to the third paragraph，what will happen when the underground heat does not dis—appear?
根据以下资料，回答下面的题目。 According to the first paragraph，one or the warnings given by the scientists is that- ACoal heats up on its Own and catches fire and burns．
- BThe underground oxygen will be used up．
- CPoisonous fumes and greenhouse gases wm be accumulated anderground．
- DThere will be an increase of abandoned mines．