形容词
1. Iron is a base metal.
铁是低值金属。
及物动词
1. Advertisements based on these facts have been printed in newspapers and magazines but have not helped much.
根据这些情况拟定的广告词登载在报纸和杂志上，但是效果不大。
名词
1. The machine rests on a wide base of steel.
这机器由一个很大的钢制底座支承。
2. That company has offices all over the world, but their base is in Paris.
这个公司的办事处遍布全世界，但本部在巴黎。
3. A bottle has a flat base.
瓶子有一个平的底。