VOA慢速英语:The Perfect Progressive Tenses

straightforward – adj. direct, not complicated

puffy – adj. larger than normal

contract - v. to make (something) smaller or shorter

certified – adj. having met the official requirements that are needed to do a particular type of work

episode - n. part of a longer program, such as a film or television series

tanned - adj. becoming more brown in color

graduated - v. successfully completed a study program

duration - n. the time during which something continues

participle - n. a form of a verb that is used to change a noun or verb