fluid n．流动性，流度 adj. 流动的
例句：Air is a fluid but not a liquid, while water is both afluid and a liquid.
空气是流体不是液体，水是流体也是液体。

fluctuate v．变动．波动，涨落
例句：The price of vegetables fluctuates according to the weather.
蔬菜价格随着天气变化而波动。

fluent adj. 流利的，流畅的
例句：Daisy likes him all the better for his fluent spoken English.
正因为他操一口流利的英语，戴茜更爱他。

flush n．脸红，激动
例句：Ellen shows a flush ofjoy at his coming.
对他的到来爱伦高兴地脸红了。

influence n．影响，感化 v．影响，改变
例句：Her parents no longer have any real influence over her.
她的父母对她不再有任何真正的约束力了。

influential adj. 有影响的，有势力的
例句：Those facts were influential in solving the problem.
邢些事实对解决问题有重大的影响。

impact n．碰撞，影响，效果
例句：The plane flew into a mountain and disintegrated on impact.
飞机冲向一座山，撞得粉碎。

compact adj. 紧奠的，紧密的 n．契约，合同
例句：The Commonwealth agreed to make a compact with this country.
英联邦同意和这个国家订约。