Answer the questions, then record two 5-min segments showing both the teacher and the students.
Click "Press to start recording". After 5 min the video will upload. Wait till 100% uploaded. Wait for 15 minutes.
Record another 5 min segment from a different point of view.
Click "Next" and "Press to start recording". Wait until the video is 100% uploaded, then click "Next".
You can start over any time.