Yes you can! Students are allowed to write and highlight in their rented textbooks. The main things to remember about rentals is to keep them dry, and to make sure to return them by the end of semester. Please let us know if you have any other questions!
I would not since they are rentals. I would write the info you think is important somewhere else so that you won't forget it. You could also use tabs on the pages and then put a note on that tab to tell you what info is important. Don't forget to remove them when you return the book though. It is nice to hand back a clean book so that someone can then take it and use it for themselves as well.
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