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twice – adv. doubled in amount or degree
journal – n. a magazine that reports on things of special interest to a particular group of people
probabilities – n. the chances that something will happen
belt – n. a region that has a lot of a particular thing
extinction(s) – n. the state or situation that results when something, such as a plant or animal species, has died out completely
arbitrary – adj. not planned or chosen for a particular reason
fragile – adj. easily broken or damaged
