river mud

例句：

1. 1.The river mud is soft and easy to walk on.
   河泥软且易于行走。
2. 2. The farmers used to collect river mud for their gardens.
   农民过去收集河泥用于他们的花园。
3. 3.The river mud was a rich source of nutrients for the plants growing in the area.
   河泥是该地区植物生长的丰富养分来源。