Hello. Is this Mr. Smith's office and the Chemistry Department?
Yes, it is. Can I help you?
Yes, I am the mother of a student in his class. I want to talk with Mr. Smith about my son's performance. Is Mr. Smith in?
No, he's having class at the moment.
Do you know when I can reach him?
He has office hours between 1:00 and 3:00 this afternoon. You can reach him after office hours.