Final answer:
The verb that completes the sentence is 'se maquille' (puts on makeup).
Step-by-step explanation:
The correct verb to complete the sentence is se maquille, which means 'puts on makeup' in English. So the complete sentence would be 'Marie doit assister à la fête. Avant de partir, elle s'habille et se maquille pour la fête.' In this context, Marie is getting ready for the party by dressing up and putting on makeup.
Learn more about Completing a sentence with the correct verb