A locomotive has to be added fuel, such as coal, firewood, or other flammable substance, consuming which may provide motion or energy for the machine.
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A locomotive has to be added fuel, such as coal, firewood, or other flammable substance and the consumption of fuel provides motion or energy for the machine.
看看文教授有沒有更好的建議。
hearth - my bad, i tought it was a typo of heart.
and the legs and wings to move on the body of animal?
By the way, combustible -> 可燃的; flammable -> 易燃的.