1. D
2. B
3. A
4. D
5. B
6. D
7. D
8. A
9. A
10. B
11. D
12. C
13. deafended
14. emigrated
15. experiments
16. inventor
17. assistances
18. introduce
19. Alexander Graham Bell worked with people who could neither speak nor hear.
20. A customer called just before he Thang Loi Delivery Service on May 12 midday.
