hydrogenKK [ˋhaɪdrədʒən] /ˈhaɪdɹədʒən/名詞1氫、氫氣Water is made of hydrogen and oxygen.水是由氫和氧組成的。2氫能、氫燃料Several bus companies are switching to hydrogen instead of diesel.好幾家客運業者正把柴油改成氫能。