I am sorry, but I can't stay until the end of class.
Where do you need to be that is more important than school?
I have an appointment.
Do you have a plan to make up your missed work?
No, but I'll make sure someone helps me out this week with my missed work.
Are you going to go right away?
I am leaving right now.
All right, but please remember that it is your responsibility to catch up.
Thanks, Professor. I'll make sure everything gets taken care of.
Goodbye, and try not to miss any more school.