Questions 8 to 10 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now， listen to the conversation.
8. Why can't Don call the professor himself?
A. Because he is in the hospital.
B. Because he has a bad cough.
C. Because he has a busy line.
D. Because he lost his voice.
9. What does the professor's assistant want him to do?
A. To cancel the class.
B. To give the midterm exams.
C. To let someone pass back the exam papers.
D. To find someone to teach the class.
10. How can the professor unlock the office's door?
A. By using the key from the department's master.
B. By using the key from the superintendent.
C. By using the key from the woman.
D. By using the key from his assistant.
