In order to fill in the blank with the most appropriate verb, we must understand the 'subject and verb agreement'. A subject is a person, thing, or a concept, in a sentence. A sentence always describes a person, thing or a concept and that is called 'subject' of the sentence. The rest of the sentence is a complement (which has the object in it). A subject and a verb should always agree in a sentence. If the subject is singular (example: Raj), the verb will also be singular (does). If the subject is plural (We), the verb will also be plural (do).