British students dominate teacher after class

I'm sorry, Isa. - I even gave you the diagram.

You know, the note you had to write was so easy.

I just didn't catch it. I'm so sorry. - Didn't catch it? Didn't catch it?

It's on the board. Look, Frenulum. It's not difficult. Frenulum.

I don't know what a frenulum was, though. You've not explained it enough.