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challenge – v. to invite someone to take part in a competition; to compete against an opponent
character – n. a person in a play, movie or television show
formal – adj. done in an official way; relating to an important or ceremonial event
casual – adj. unofficial; done without much thought
topic – n. subject
etymology – n. an explanation of where a word came from : the history of a word
stoicism – n. the quality or behavior of a person who accepts what happens without protesting or showing emotion
introduce – v. to bring into use or operation; to make someone known to another person
grammar – n. the system and structure of a language
dad – n. someone's father
