'Do' And 'does' are each forms of your present indefinite tense with the verb 'to complete.' Which a person you will use will generally rely upon the sentence's subject. Their utilization is sort of similar, apart from 1 instance where You need to use 'do' instead of 'does.' There https://financefeeds.com/gcex-expands-spot-commodities-offering-with-eight-new-products/