'Do' and 'does' are the two forms on the existing indefinite tense with the verb 'to complete.' Which one you can use will generally rely on the sentence's topic. Their usage is sort of identical, except for 1 instance where You can utilize 'do' and never 'does.' This procedure https://financefeeds.com/b2prime-appoints-stuart-brock-as-institutional-business-development-manager/