'Do' and 'does' are both equally forms of your existing indefinite tense on the verb 'to complete.' Which just one you can use will primarily depend upon the sentence's matter. Their usage is sort of equivalent, apart from one instance where You need to use 'do' instead of 'does.' https://financefeeds.com/copyright-ai-gives-price-predictions-for-ethereum-xrp-and-solana-by-end-of-2025/