Ответ:
1. You have to work hard if you want to become a doctor. It is not easy.
2. You have to come with me. I'm the only one who knows how to get there.
3. We have to do something to protect the environment.
4. You don't have to give me a lift. I will walk.
5. You don't have to do the washing up. Patty has done it already.
6. You
don't have to go to the desert to see camels. You can see them at the zoo.