Помогите, пожалуйста, с английским.Преобразуйте предложения по образчику, обращая внимание на

1. if he works hard, he will pass the exams well.
 a) if he worked hard, he would pass the exams well.
 b) if he had worked hard, he would have passed the exams well.

2. If they finish their work quickly, they will go home early.
 a) If they finished their work quickly, they would go home early.
 b) If they had finished their work quickly, they would have gone home early.

3. If you don't listen to the teacher, you will learn nothing.
 a) If you didn't listen to the teacher, you would learn nothing.
 b) If you had didn't listen to the teacher, you would have learnt nothing.

4. If he lives in England, he will go to Oxford University.
 a) If he lived in England, he would go to Oxford University.
 b) If he had lived in England, he would have gone to Oxford University.