Ответ:
1. If..., I'll get a bad mark.
2. If..., I'll not finish my homework.
3. If..., I'll stay at home.
4. If..., I'll ask him for an autograph.
5. If..., I'll not rest.
6. If..., I'll thank you very much
7. If..., he must be sick.
8. If..., she usually sleeps.