A pan was boiling on the stove, steaming up the windows.

【steam】一锅东西在炉子上煮沸了，窗户上都是水汽。

But Hiccup hadn't noticed Snotlout's boat, Sparrowhawk, steaming up behind him at great speed.

但是卡嗝没有注意到鼻涕虫的船--斯巴罗霍克号--正以极快的速度在他身后驶来。