Rewrite these sentences, using Conditional Sentences

B. Rewrite these sentences, using Conditional Sentences
1. I'd like to go with you tonight but I am very busy.

2. She wasn't able to answer the questions, so she failed the exam

3. The reason why I didn't phone you was that I didn't know your phone number

4. Without the sun, we wouldn't exist

5. Peter was very nervous and failed the driving test

6. I can't tell you what time it is because I don't have a watch

7. She didnn't learn mathematics: that's why she was cheated by that salesman

8. We missed the train because the clock wasn't right

9. The dress is very expensive, so she can't buy it

10. The teacher was very angry. His pupils did their homework carelessly