6 prepare video July 8, 2019 16 32 64 128 Prepare 6 video unit 16 Prepare 6 video unit 12 Prepare 6 video unit 3 Prepare 6 video unit 11 Prepare 6 video unit 18 Prepare 6 video 11 Prepare 6 video unit 13 Prepare 6 video 12 Prepare 7 audio Navigate pre-intermediate video unit 6 Prepare 7 workbook