篝火熄灭后，木炭仍在闷烧，冒出缕缕青烟。

After the campfire went out, the charcoal kept ___smouldering with wisps of smoke rising.

尽管她面带微笑，但内心对不公平的待遇依然愤愤不平。

She smiled politely, but anger was ___smouldering inside her over the unfair treatment.