Use CAN, MAY, CAN'T or MAY NOT

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

He  call me up. He doesn't know my phone number.
 I ask you to help me with my luggage, please?
I
 not drink any alcohol. It is not allowed when you are on duty.
What
 we do now? He won't listen to us.
I
 speak to you. He is listening.