Is it appropriate to censor textbooks for material that could be objectionable to a group?

An excerpt from “Teachers , Schools, and Society “ by Myra and David Sadker pg. 409-412 in ACR Chapter 11, 4th edition (The Art of Critical Reading) ISBN: 978-0-07-351359-1 QUESTION IS: Is it appropriate to censor textbooks for material that could be objectionable to a group? Or is it important for children to read textbooks that contain controversial or objectionable thoughts or expressions. I also want to add that i need an outline that i turn in with the essay in class