孩子们兴奋地看着装满火药的烟花在天空中绽放。

The kids watched excitedly as the fireworks, filled with ___gunpowder, burst in the sky.

这个话题在紧张的谈判中就像火药，可能引发激烈的争论。

This topic is like ___gunpowder in the tense negotiation, likely to trigger heated arguments.