1) Young people __________ obey their parents.  
**A. must**

2) You should leave early so that you __________ miss the bus.  
**C. won't**

3) Gill __________ play the piano. She has never studied it.  
**C. can't**

4) I hope I __________ find it.  
**A. can**

5) They __________ get up early today, because it's Sunday.  
**D. needn't**

6) This box isn't as heavy as it looks. You __________ help me with it.  
**D. needn't**

7) You __________ play loud music at night. The neighbours will call the police.  
**A. mustn't**

8) You __________ stand up. There are a lot of seats available on the bus.  
**C. needn’t**

9) People __________ at the park after they use it.  
**C. ought to**

10) This library book is __________ overdue. I __________ better return it today.  
**D. had**  
(Note: "had better" is commonly used in this context to express urgency.)

11) Our company provides free advice on the use of our products. You __________ pay us.  
**C. needn’t**

12) Your health is getting worse. You __________ quit smoking.  
**A. should**

13) You __________ take along some cash. The restaurant may not accept credit cards.  
**A. had better**

14) You __________ forget to pay the rent tomorrow. The landlord is very strict about paying on time.  
**C. mustn't**

15) “Must I take my umbrella?” - “No, you __________. It’s not going to rain.”  
**C. needn’t**