natural & manufactured timbers

Cliciwch isod i weld yn Google Slides neu "edit" os oes gynych yr hawl:

https://docs.google.com/presentation/d/1LpPyKCDewperKGrqKaLTA9wNZgPsJbR-MaQnyMNZP3M/edit#slide=id.g23288151d0_0_0