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battery – n. a container made of one or more cells, in which chemical energy is used to create power
fellow – n. a member of a group; a person appointed to a position for study or research
application - n. use; a way of using something
portable – adj. able to be carried or moved from place to place
volt – n. a measurement of electrical force
commercially – adv. related to being able to be sold to people and used widely
benefit – n. something that produces helpful or good results
context – n. additional information that helps explain some statement, action or incident
