'Do' and 'does' are both forms in the existing indefinite tense from the verb 'to complete.' Which 1 you will use will primarily rely upon the sentence's issue. Their usage is sort of equivalent, aside from one particular occasion where You need to use 'do' instead of 'does.' Ebb https://financefeeds.com/schiff-introduces-coin-act-to-restrict-copyright-profiteering-by-public-officials/