I'm sorry, I didn't understand. You're speaking too quickly.
I didn't get that down. Could you say it again? Could you repeat the last bit?
I missed the beginning of what you said. Could you explain again, please?
Shall we do the exercise in our work books? Are we supposed to finish this off at home?
What do we have to do next? Could you write it up on the board, please?
Is it my turn? (Am I next? Shall I start?)