running sand

例句：

1. 1.The river is running with a strong current.
   这条河正在强劲地流动。
2. 2. The car was stuck in the flowing sand.
   汽车被困在流动的沙子中。
3. 3. The children were playing in the flowing sand.
   孩子们在流动的沙子中玩耍。