实验室通过调整氧气浓度,观察火焰颜色和燃烧效率之间的关系。Shíyànshì tōngguò tiáozhěng yǎngqì nóngdù, guānchá huǒyàn yánsè hé ránshāo xiàolǜ zhījiān de guānxì.By adjusting oxygen concentration, the laboratory observed the relationship between flame colour and combustion efficiency.
蜡烛的火焰被风吹得轻轻摇晃。Làzhú de huǒyàn bèi fēng chuī de qīngqīng yáohuàng.The candle flame swayed gently in the wind.
篝火的火焰越烧越高,照亮了周围的帐篷。Gōuhuǒ de huǒyàn yuè shāo yuè gāo, zhàoliàng le zhōuwéi de zhàngpeng.The campfire flames rose higher and higher, lighting up the tents around it.