在海滩上散步后，我感到鞋子里有一粒细小的沙子。

I felt a tiny grain of ___sand in my shoe after walking on the beach.

孩子们整个下午都开心地在沙子里玩耍，堆砌城堡。

The children happily ___played in the ___sand and built castles all afternoon.

这片海滩上的沙子非常细腻柔软，非常适合赤脚行走。

The ___sand on this beach is very fine and soft, perfect for walking barefoot.