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challenging – adj. difficult in a way that is usually interesting or enjoyable
crossword puzzle – n. a puzzle in which words that are the answers to clues are written into a pattern of numbered squares that go across and down
geriatric – adj. of or relating to the process of growing old and the medical care of old people; of or relating to geriatrics
regular – adj. happening over and over again at the same time or in the same way : occurring every day, week, month, etc.
supplement – n. something that is added to something else in order to make it complete
