听一段材料，回答下面几个小题。
Who is the man probably speaking to?
A. Children.
B. Students.
C. Teachers.
Where is the speaker?
A. In the classroom.
B. In the library.
C. In the office.
How does the man treat his job?
A. He doesn't care about it.
B. He is serious about it.
C. He is tired of it.