B/ Pass form 1. The teacher explains the lesson

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1. The lesson is explained by the teacher.

2. The food is being cooked in the kitchen by Mrs. Green. 

3. That noise was made by these boys. 

4. English is spoken all over the world. 

5. He was given back the money by me last Sunday. 

6. These exercises can't be done quickly by Nga. 

7. The bill has to be paid before the first of the month. 

8. You will be asked some questions. 

9. The box has been locked and it can't be opened by me. 

10. I want this work to be done by you now. 

11. That silly thing shouldn't be done by him. 

12. Some exercises are done by Nam every day. 

13. English is taught by the new teacher. 

14. That machine hasn't been used for ages. 

15. All the eggs have been eaten by her.