Final answer:
The correct verb form in Spanish is 'somos'
Step-by-step explanation:
The correct verb form to complete the question 'María y yo ____ amigos' is somos. The subject 'María y yo' corresponds to the pronoun 'we', so we need to use the form of the verb 'ser' (to be) that matches with 'we'. In Spanish, 'we' is expressed as 'nosotros', and the corresponding form of 'ser' is 'somos'. Therefore, the correct sentence is 'María y yo somos amigos'.
Learn more about Verb forms in Spanish