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

Решение:

1. You don't have to go to the desert to see camels. You can see them at the zoo. (Нет необходимости, потому что есть возможность увидеть их в зоопарке)
2. You have to work hard if you want to become a doctor. It is not easy. (Необходимость, потому что это условие для достижения цели)
3. You don't have to come with me. I'm the only one who knows how to get there. (Нет необходимости, потому что говорящий сам справится)
4. We have to do something to protect the environment. (Необходимость, потому что это важно для всех)
5. You don't have to give me a lift. I will walk. (Нет необходимости, потому что говорящий предпочитает идти пешком)
6. You don't have to do the washing up. Patty has done it already. (Нет необходимости, потому что дело уже сделано)

Ответ: don't have to; have to; don't have to; have to; don't have to; don't have to.