Can coal be clean?
D000397:Air Pollution / Q000517:prevention & control*; D002245:Carbon Dioxide / Q000302:isolation & purification*; D003031:Coal; D003246:Conservation of Energy Resources / Q000379:methods / Q000639:trends; D017752:Greenhouse Effect; D038622:Internationality; D011210:Power Plants / Q000592:standards
D003031:Coal; D002245:Carbon Dioxide