7. How many times_________ you________________ \(listen\) to this dialogue? – I__________________ \(listen\) to it three times. Frankly speaking, I____________________ \(listen\) to this dialogue for half an hour but_______________________ \(not understand\) a word.

• have / listening / have listened / have been listening / do not understand
• have / listened / have listened / have been listening / have not understood
• have / listened / have been listening / have listened / have not understood