1. Advanced 4A Unit 5 Workbook key

2. 1. Vocabulary and expressions A 1. Authorities 2. Vanished 3. Theory 4. Witness 5. Documents 6. Devoted 7. Seemingly 8. Identified 9. Distress call 10. Stranded 11. Outcome 12. Sought 13. Evidence 14. Involvement 15. Incident

3. B a. 3 b. 1 c. 2 d. 4 e. 6 f. 5

4. 2. Grammar A 1. She must not have studied. 2. She might not have gotten enough sleep. 3. She may not have attended enough classes. 4. Their friends may have missed the bus. 5. Their friends might have forgotten about their appointment. 6. Their friends could have gotten lost. 7. He must have stayed out late last night. 8. He might have gone to a party last night. 9. He may have studied all night long. 10. She might have gotten an e-mail from her friend. 11. She could have won a game she was playing. 12. She may have found a wonderful shopping website.

5. B 1. You couldn’t have written this paper yourself. 2. Jim Thompson must not have planned his disappearance. 3. Jim Thompson must have wanted to vanish. 4. Our teacher may/ might have forgotten about our quiz today.