fluid savings

例句：

1. 1. The water in the bottle is very fluid.
   瓶子里的水非常流动。
2. 2. The river flows through the valley.
   这条河穿过山谷流淌。
3. 3. The oil is a fluid that can be poured easily.
   油是一种可以轻易倾倒的流体。