Решение с исправлением ошибок, и 15 баллов Ваши.

3. The ship sank because the engineer didn't call for help until it was already sinking. 4. The reason I get fat is that I'm always tasting things while I'm cooking. _right_ 5. How is Jennifer? Has her health improved? 6. You're quite right, I completely agree with you. 7. What did you do after you left school? 8. Now I understand what you're trying to say! __right__ 9. I can't imagine why you  believe all those rumours. 10. Martin was looking forward to a peaceful weekend, when his brother arrived with all his friends from the football club.11. Philippa heard the result of the election as she was driving to work. So she phoned me when she got there. _right_ 12. Oh, I'm so sorry, I've spilt some tea. Where do you keep the paper towels?