Продолжите предложения, используя конструкцию to have to в прошедшем и будущем

Продолжите предложения, используя конструкцию to have to в прошедшем и будущем медли:
1. The weather was bad yesterday, that's why..........(to stay at home).
2.1 left my watch at home, that's why ..........(to return).
3. My sister invited her friends to us yesterday, that's why..........(to buy atat of food).
4. My father didn't want to have fish for dinner, that's why..........(to cook meat).
5. My mother didn't let me go to the party, that's why..........(to play computer games).
6.1 forgot to translate an article at home, that's why.......... (to translate it before the lesson).
7. We forgot to buy sugar, that's why..........(to have tea without sugar).
8. She made a lot of mistakes in her exercises, that's why..........(to correct).
9. My friends were waiting for me at the railway station, that's why..........(to hurry).
10. My friends were not right, that's why .........(to give advice).
11. There are no cups in our office, that's why..........(to bring cups to the office tomorrow).
12. There is no light in our office, that's why..........(to return home).
13. We receive a lot of letters from Germany, that's why..........(to learn German next year).
14. My aunt is in trouble, that's why..........(to help soon).
15. My sister doesn't know what to do, that's why..........(to tell the truth).