A problem about imported lessons

My last two or three imported lessons have space between lines.
I want to delete the lines so that I can do Lingqing phrases that are separated by blanc lines.
How can I edit that?
Thank you.

@chikaraishihara - Select “Edit Lesson” from the drop down at the top of the lesson (small settings icon) next to the audio player. When edited, click “save” or “save and open”.