These are good questions for which I have offered no answer. I remember when I taught, the teachers in a discipline, such as the "social studies" teachers, chose the history books. I never thought that created much of a problem. However, I do recall that the Humanities teacher glued together pages of every textbook because they included the "Miller's Tale" from Chaucer (or was it "The Wife of Bath?") and that included the word "farting".