烛心

例句：

1. 1. The candle's wick is almost burned out.
   蜡烛的芯几乎烧完了。
2. 2. The wick of the candle flickered in the wind.
   蜡烛芯在风中闪烁不定。
3. 3. The candle's wick was so thin that it could not hold the flame.
   蜡烛芯太薄了，无法保持火焰。