Some fluid was flowing from the tree.一些液体正从树里流出来。
The little boy is taking cold fluids.那个小男孩正在喝冷饮。

［同义词］ adj. adaptable, changeable, liquid, watery
［反义词］ adj. fixed, hard, settled, solid
［词源］＜拉丁语fluere(流动)

用作定语
▲～+n.
 Water is a fluid substance.水是流体。
Well, we have not enough fluid capital.可是,我们没有足够的流动资金。
用作表语
▲S+be+～
 The weather is fluid in summer.夏天天气多变。
用作宾语补足语
▲S+V+O+～
 Keep your plans fluid until we decide what we're going to do.在我们决定怎么办之前,不要把计划定得太死。