VOA慢速英语:名师问答：buy和purchase的区别

formal – adj. related to serious or official speech and writing

hamburger – n. a flat, usually round piece of ground beef that is cooked and served usually in a roll or bun

conqueror – n. a person who takes control of a country or city through the use of force

Anglo-Saxon – n. the language of the Anglo-Saxons

summary – n. a brief statement of the main points of something