Answer:Here are the sentences filled in with the appropriate modals:1. She can speak three languages but none of them well. (ABILITY)2. Students, you must finish your assignments by the end of the day. (OBLIGATION)3. You must not say things like that to your sister. (PROHIBITION)4. You must not take photos in the museum. They're really strict about it. (PROHIBITION)5. Could you speak English when you were a child? (ABILITY)