(Kelly reads another clue with the monitor.) In poetry, it's a foot or metrical unit consisting of an unstressed followed by a stressed syllable
..... is English K-12 
teachers, we have prepared this book and its ...... processing unit, monitor, 
keyboard, speakers, drives of various ...... consists of at least one stressed 
syllable (its energy peak) and one or two ..... Metrical Phonology: A Coursebook.