Questions 4 to 7 are based on the following conversation. At the end of the conversation, you will be given 20 seconds to answer the questions. Now listen to the conversation.

What is the attitude of the man towards his job

A．One should know the jobs and living places of his customers.
B．One can face the same challenges as his colleagues.
C．One can identify the publications his customers read.
D．One can evaluate himself.

A．Because math was the most difficult course.
B．Because it was a federal exam and is fair.
C．Because math could reflect the teaching quality in a better way.
D．Because all students took the math exam.