Filaments can be constituted-of-or-filled-with (hydrogen gas).Logical formLearned from3 sentences. (Hydrogen atoms) may undergo a recombination.Logical formLearned from3 sentences. Emission can be from (hydrogen gas).Logical formLearned from3 sentences. Model may show (hydrogen atom).Logical formLearned from3 sentences. A (hydrogen processing) can be costly.Logical formLearned from3 sentences. A material can be for (hydrogen storage).Logical formLearned from3 sentences. Hydrogen may be extracted from variety of fuels.Logical formLearned from3 sentences. A role can be in a (hydrogen initiative).Logical formLearned from3 sentences. A (hydrogen economy) may pertain-to the future.Logical formLearned from3 sentences. A (hydrogen economy) may minimize a dependence.Logical formLearned from3 sentences. A molecule may be composed of some (hydrogen atoms).Logical formLearned from3 sentences. A hydrogen may cool.Logical formLearned from3 sentences. (Fuel cells) may run on hydrogen.Logical formLearned from3 sentences. A (hydrogen production) may pertain-to persons.Logical formLearned from3 sentences. Hydrogen may be produced from fuel.Logical formLearned from3 sentences.