Ответ:

1.The bell must ring now.

2.This book must be in the library .

3.He must have recognized you by the photo in the papers.

4. He must be in at this time.

5. She must be trying to help you.

6. She must be waiting for you at home.

7. He must have been already ill .

8. The first experiment must have been failed.

9. She must have known what she was going to do.

10.She must be fond of the child.

11. They must have taken the wrong turning .

12. He must be taken there by car.