foam glass block

例句：

1. 1. The foam on the surface of the milk is due to the air trapped inside.
   牛奶表面的泡沫是由于里面的空气被困住造成的。
2. 2. The foam was so thick that it covered the entire surface of the pool.
   泡沫很厚，覆盖了整个游泳池的表面。
3. 3. The foam rose up and floated to the top of the glass.
   泡沫浮起并漂浮到玻璃杯的顶部。