火灾是由香烟的一个火花引起的。

The fire was caused by a ___spark from a cigarette.

当最后一点火花停止闪烁时，所有人都起立唱起了国歌。

As the last ___spark ceased to glow, all the people stood up and sang the national anthem.

从篝火中溅出的一个火星落到了我的袖子上。

A stray ___spark from the bonfire landed on my sleeve.