1. extra
a. ①额外的：extra pay for extra work 加班费
②特别的：all extra edition 特刊
n. 额外的东西，附加费用：Meals are all extra.
adv. 特别地：work extra hard 工作非常努力
2. factor
n. 因素，要素：Ability, industry and health are factors of success.
3. fair
a. ①公平的，公正的，合理的：fail play 公平竞争
②相当大的，尚好的，充足的：A fair amount of rain has fallen.
③金发的，(肤色)白皙的：a fair haired girl 金发女郎
④(天气)晴朗的：fair weather 晴朗的天气
fair n. ①定期市集，庙会：a farm produce fair 农产品集市
②博览会，交易会：a world's fair 世界博览会
fairly adv. ①公正地，公平地：I felt I hadn't been treated fairly.
②相当，还算：It's fairly hot today.