(Hydrogen fuel tanks) can be liquid.Logical formLearned from6 sentences. An atmosphere may contain hydrogen.Logical formLearned from6 sentences. (Hydrogen concentrations) can be high.Logical formLearned from6 sentences. Measurements may show presence of amounts of hydrogen.Logical formLearned from6 sentences. Progress can be in (hydrogen combustion engines).Logical formLearned from6 sentences. A (hydrogen economy) can be competitive.Logical formLearned from6 sentences. A (hydrogen initiative) may move toward demonstratting (hydrogen producing technologies).Logical formLearned from6 sentences. A (hydrogen initiative) may focus on (hydrogen production technologies).Logical formLearned from6 sentences. A focus may lead to production of hydrogen.Logical formLearned from6 sentences. Code can be specific to hydrogen.Logical formLearned from6 sentences. Hydrogen may be derived from water.Logical formLearned from6 sentences. A hydrogen may run_out.Logical formLearned from6 sentences. Atmospheres can be constituted-of-or-filled-with hydrogen.Logical formLearned from6 sentences. (Hydrogen sulfide) may emanate from oil.Logical formLearned from6 sentences. Sour gas may contain a (chemical hydrogen sulfide).Logical formLearned from6 sentences.