The assassination of Austria's Archduke Franz Ferdinand in the city of Sarajevo was the spark that set off the explosion.

VOA: special.2010.10.07

It all sort of depends on how you hit it off with somebody, whether there's a spark.

这要看你是不是跟那个人合得来，能不能擦出火花。

跟校友们的关系 - SpeakingMax英语口语达人