Working with Audio on the Edit Page

What must you select before you can add a marker to the timeline ruler?

Where do you find a list of all the markers in the timeline?

How do you add a keyframe to an audio clip’s volume line in the timeline?

What can you do in the Normalize Audio dialog?

Set a target level in dbfs for the loudest peak in the selected clips.
Normalize the audio channels so that all channesl (left and right for 2.0 Audio) are equally loud.
Identify and remove sounds like distortions, feedback loops, humming and more. If successfull, a so called normalized track remains.
Set the metadata of the audio track to EN_US.

When reading an RMS/Peak meter in the edit page, audio that is around -5 dBFS is very quiet.