Using the same pfd in multiple google classes

I would like kami to uses different version of the same master pdf. I teach 3 lecture classes and I am constantly deleting my own annotations from the previous lecture class inorder to present the information as “new” to my next class. I would like Kami to utilize the “Template” copy made with each google classroom as its default file. Currently kami will add the annotations to my master file only. So when I bring up my 7th period class, the notes from my 1st period presentation/annotations shows up. The master file ten contains all the annotations from every class session. I know this because I can restore all 200+ annotations… Any constructive advice would be appreciated.