Distinguir entre "mustn't" y "don't/doesn't have to"

You ..... ask for permission to go out. You are old enough to know what you are doing.
1. mustn't
2. don't have to
You ..... be late or you won't be able to enter the exam room.
1. mustn't
2. don't have to
The flight to New York is nonstop. We ..... change planes this time.
1. mustn't
2. don't have to
You ..... park here or you will be fined.It's an emergency exit.
1. mustn't
2. don't have to
You ..... show me out. I know the way.
1. mustn't
2. don't have to
You ..... wear a suit on Fridays. It's "dress down" day.
1. mustn't
2. don't have to
I'll tell you a secret but you ..... tell anybody else.
1. mustn't
2. don't have to
In football you ..... touch the ball with your hand.
1. mustn't
2. don't have to
You ..... turn the light on when I'm in the photography lab.
1. mustn't
2. don't have to
I like the weekend because I ..... work.
1. mustn't
2. don't have to