Though hydrogen-powered cars were developed a long time ago, liquid hydrogen evaporates, while gaseous hydrogen requires vast amounts of storage space, and if the gaseous form explodes, it is highly dangerous.
雖然以氫為燃料的汽車早已研發出來，但液態氫會蒸發，而氣態氫儲存起來體積龐大，宛如氣體炸彈，危險性高。