New Libra Color user

I'm new to Kobo, and I have a few questions.

Is there a good science dictionary I can add to my Kobo?

Is there a way to make a screen print without having to go in and modify the system (I'm not that courageous!)

I have a lot of highlights in a side-loaded PDF that I'd like to print out - is there a way to view the file on my computer where I wouldn't lose those highlights but could do screen prints off my computer monitor?

Thanks!