froth fire extinguisher

例句：

1. 1. The milk had a thick layer of foam on top.
   牛奶上面有一层厚厚的泡沫。
2. 2. The frothy coffee was delicious.
   这杯泡沫咖啡很好喝。
3. 3. The foam on the surface of the milk seemed to be rising up.
   牛奶表面的泡沫似乎在上升。