Ответ:
1. If you want to be healthier, think carefully about *the food* you eat.
(the food, так как речь идёт о еде которую ты знаешь ).
2. If you don't enjoy exercise do something else.
3. Do you eat enough the fruit and vegetables.
4. Piece of chocolate cake should only be eaten occasionally
5. If you have had a bad day, try and do something nice for yourself.
6. We opened two shops last summer. since then, we had opened two more.
7. It is getting colder in the room because the window is open
8. Bob Dylan become one the most famous singer of all times
9. You leave the hall immediately
10.Well, i love traveling since , i had been a student back in 1980s , and i had wanted to work with people.