You will ask your teacher about a certain lesson you don't understand.What you say?

excuse me sir/miss/mr* I want to ask you about this .......** because I don't understand with that
*plih salah satu
**materi yg blum paham
#maaf klo slah yakk

I'm sorry/Excuse me, sir/miss. Could you please explain to me about this lesson again? I don't quiet understand about it