Rewrite 1. The bus was so crowded that she had to walk to the office. → If
2. He gets up early. This is why he gets good health.
→ If.
3. She is weak, so she doesn't go out very often.
→ If
4. As the sun was in the right direction, the photographs came out very well.
→ If.
5. He watches video film by night. Therefore, he feels asleep by day.
If
6. He failed in the examination because he was too lazy.
→ If ...
7. He drives carelessly so he will have a serious accident.
→ If.
8. I missed the meeting because my car broke down.
→ If
9. He doesn't study hard so he will fail the final exam.
→ If
10. Susan is overweight because she eats too much.
→ If..​