fine sand

例句：

1. 1. The beach is covered with fine sand.
   海滩上铺满了细沙。
2. 2. Fine sand can be used to make sandcastles.
   细沙可以用来建造沙堡。
3. 3. The river flows through a valley filled with fine sand.
   河流流经一个山谷，山谷里满是细沙。