C. Underline the correct words. 16. You can have a picnic/watch a film in the park. 17. You can see works of art/exercise at the gallery. 18. You can find a book/have a snack at a fast food restaurant. 19. You can see fish/watch football at the stadium. 20. You can buy things/see animals in a department store. D. Underline the correct item. 21. You must/can't have a party in here. It's not allowed. 22. He must/mustn't park his car here. It's not allowed. 23. You must/can't do your homework. That's the rule. 24. You must/can't wear a seatbelt when you're in a car. That's the law. 25. You must/mustn't eat in the library. It's forbidden.

Here are the answers with explanations: **C. Underline the correct words.** 16. You can have a **picnic**/watch a film in the park. * *Explanation:* Parks are places for picnics. 17. You can see **works of art**/exercise at the gallery. * *Explanation:* Art galleries are where works of art are displayed. 18. You can find a book/have a **snack** at a fast food restaurant. * *Explanation:* Fast food restaurants are places where you have snacks. 19. You can see fish/**watch football** at the stadium. * *Explanation:* Stadiums are for watching sports, like football. 20. You can **buy things**/see animals in a department store. * *Explanation:* Department stores are for buying things. **D. Underline the correct item.** 21. You must/**can't** have a party in here. It's not allowed. * *Explanation:* If something is not allowed, you can't do it. 22. He must/**mustn't** park his car here. It's not allowed. * *Explanation:* If something is not allowed, you mustn't do it. 23. You **must**/can't do your homework. That's the rule. * *Explanation:* If it's a rule, you must do it. 24. You **must**/can't wear a seatbelt when you're in a car. That's the law. * *Explanation:* Laws dictate what you must do (wear a seatbelt). 25. You must/**mustn't** eat in the library. It's forbidden. * *Explanation:* If something is forbidden, you mustn't do it.