guo jia ji shi you tian ran qi qi kan
天然气 hai shang tian ran qi lei de s c i qi kan
shi you tian ran qi fang mian de qi kan
工程 shi you tian ran qi gong cheng lei qi kan
shi you tian ran qi hao fa de qi kan
shi you tian ran qi lei de e i qi kan
地质 shi you tian ran qi lei di zhi qi kan