Here are the answers to the questions:
11. The boy looked B. confused when he saw his parents at the door of the classroom.
12. Jimmy walked down the road without looking C. at anybody.
13. The teacher let the little boy A. go home early because he felt ill.
14. The doctor A. advised me not to stay up too late at night.
15. Do you know who's B. taking over his pottery workshop?
16. If you don't D. carry on with your regular exercise, you will gain more weight.
17. It took my aunt a long time to C. get over the death of her pet dog.
18. We'll have to D. set up more schools to meet the demands of the increasing numbers of children.
19. Alan: "Thank you very much for your help" - Karen: D. You're welcome
20. Luci: "I'm taking my TOEFL test tomorrow" - Kate: B. Good luck