Answer :

aestheticallystars
I would say read closely and highlight any important details. If the textbook belongs to the school and you're not allowed to write on it, take some notes and write down the important details on a different piece of paper.

The reading strategy that is the best when you are trying to make sense of and retain the information in a textbook is to read closely and try to remember the key words and make connections between them. If you do this, it will be easier to remember the text and you will also be able to explain it in your own words.