Sure! Here are the rewritten sentences:

1. We rarely visit you since you live so far away.
2. Remain silent, or you won't grasp the lesson.
3. The accident occurred because the driver in front suddenly stopped.
4. He's overweight because he doesn’t exercise.
5. She didn't purchase a coat due to a lack of funds.
6. Drive carefully; otherwise, you may encounter an accident.
7. We can’t have lunch in the garden due to the rain.
8. Bring a raincoat; otherwise, you'll get wet.
9. I can’t meet you tomorrow evening because I need to work.
10. She skipped eating because she wasn't feeling hungry.
11. If you don’t study hard, you will fail the exam.
12. If I have time, I will help you.