the audio on this whole lesson seems to have disappeared since they change the look of the site. The previous two lessons and other practice has been fine
The best place to report this is in the Duo troubleshooting forums - just look on the web for 'duo troubleshooting discussion' or similar.
We did ask Duo a short while ago to update the sound on both the new Tree 2 and also to refresh it on the original Tree 1 - this may still be in progress, but we have no way of knowing directly.
It's ok now again. I don't know what happened but for that whole lesson it wasn't there. I didn't know there were two trees. How do I know which one I am using?