Simple past tense and past participle of complete.(verb)
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Use "completed" in a sentence
"The Bible teaches us of a Creation as a definite act, completed at a definite period in the past, and it gives us the Sabbath as the divine memorial of this _completed_ Creation."
"A publication under the same title completed the course."
"The good news, based on research that we and our colleagues at McKinsey & Company recently completed, is that the United States could dramatically increase the number of top students who choose teaching by adopting some of these countries 'practices."