Content creation

I have a drag and drop activity with an image that users drag words on to. It is all working fine except that when I change the opacity of the draggable text to zero, the opacity stays the same. It looks fine when I am editing it, but when I view the activity the opacity has not changed. Any suggestions for where I might be going wrong? I have attached three images showing the settings are at 0 opacity, the screenshot showing how this looks in edit mode, and the screenshot showing how it looks in view mode.

Why is it that when I try to copy an existing activity and then attempt to paste and replace it in a new activity, the 'paste & replace' option doesn't work?

Hello,

don't ask to ask, just ask is something I have to remind myself again and again.
I was planning to include a single choice task within a course presentation. Actually, my thought was that I wanted to include an audio output outside of this task, which would have had to be decided. Then I saw in the preview under Lumi that single choice also contains a loudspeaker symbol. Unfortunately, I didn't see the option to add an audio file anywhere in the edit mode.
Can someone please show me where this is possible.
Regards Villon