flow around a body

例句：

1. 1.The river flows gently over the rocks.
   河水缓缓流过岩石。
2. 2. Theair flows freely throughthe ventilation ducts.
   空气自由地通过通风管道流动。
3. 3. The water flows steadily down thehillside.
   水沿着山坡稳定地流淌。