7. he was not in town, therefore he was not present at our meeting. if . 8. the pavement was so slippery that i fell and hurt my leg. if . 9. the sea is rough, and we cannot sail to the island. if . 10. they made a fire, and the frightened wolves ran away. if . 11. it is late, and i have to go home. if . 12. i was expecting my friend to come, that's why i couldn't go to the cinema with you. if . 13. he always gets top marks in mathematics because it is his favourite subject and he works a lot at it. if . 14. i didn't translate the article yesterday because i had no dictionary. if . 15. we lost our way because the night was pitch-dark. if . 16. the box was so heavy that i couldn't carry it. that's why i took a taxi. if .