Final answer:
The appropriate verb to fill in the blank is 'hablan', which means 'to speak' in Spanish.
Step-by-step explanation:
The appropriate verb to fill in the blank in the sentence is hablan. The subject of the sentence is 'Uds.' which is the abbreviation for 'ustedes' meaning 'you all' in Spanish. The verb 'hablan' is the third person plural form of the verb 'hablar' which means 'to speak'.
Learn more about verb conjugation in Spanish