As you probably guessed, all three stories are deeply biased. (1) Emphasis on a "daunting" climb implies that blindness is some sort of disability, when it should be viewed as just another personal attribute, like hair color. Besides, mountain-climbing stories are examples of "regional bias," unfair to readers who live in deserts, cities and rural areas. (2) Dinosaurs are a no-no -- they imply acceptance of evolutionary theory. (3) Making the girl's mother a professor perpetuates the "model minority" myth that stereotypes Asian-Americans. Older people must not be shown playing checkers. They should be up on the roof fixing shingles or doing something vigorous. And pizza is a junk food. Kids may eat it -- but not in a school story.

That's what's going on in schools these days. Diane Ravitch's new book, "The Language Police," documents "an intricate set of rules" applied to test questions as well as textbooks. A historian of education who served as an assistant secretary of education for the first President Bush, Ravitch offers many eye-catching cases of subjects vetoed: peanuts as a good snack (some children are allergic), owls (taboo in Navajo culture), and the palaces of ancient Egypt (elitist).

Back in the 1980s and '90s, lots of us chuckled at the spread of the "sensitivity" industry in schools. Words were removed from tests and books lest they hurt someone's feelings, harm the classroom effort or impair morals. Most of us assumed that this was a fad that would soon disappear as grown-ups in education exerted the rule of reason.

But ridicule had little effect, and grown-ups either converted to the sensitivity ethic or looked the other way. Textbook publishers, with millions of dollars at stake, learned to insulate themselves from criticism by caving in to all objections and writing craven "guidelines" to make sure authors would cave, too.

Ravitch warns that these guidelines amount to a full-blown form of "censorship at the source" in schools, and "something important and dangerous" that few people know about. She blames both the religious right and the multicultural-feminist left. The right objects to evolution, magic and witchcraft, gambling, nudity, suicide, drug use, and stories about disobedient children. The left objects to "sexist" fairy tales, Huckleberry Finn, religion, smoking, junk food, guns and knives, and what some guidelines call "activities stereotyping" (blacks as athletes, men playing sports or working with tools, women cooking or caring for children).

What started out as a sensible suggestion -- don't always show women as homemakers or minorities in low-level jobs -- developed into hard reverse stereotypes (women must not be shown in the home, maids can't be black). "In the ideal world of education-think," Ravitch writes, "women would be breadwinners, African-Americans would be academics, Asian-Americans would be athletes, and no one would be a wife or a mother."

Whites are a group, perhaps the only group, not protected by smothering sensitivity. This follows multicultural dogma. One set of guidelines (McGraw-Hill) "express(es) barely concealed rage against people of European ancestry" as "uniquely responsible for bigotry and exploitation," Ravitch notes.

What can be done? Ravitch recommends eliminating the current system in which many states adopt textbooks for all their schools. She says it results in cartel-like behavior that allows extremists to manipulate textbook requirements, particularly in the two big states that matter most, California and Texas. Opening up the market, she thinks, would free teachers to choose biographies, histories or anthologies, rather than sensitivity-laden textbooks.

Panels that analyze tests and texts should include teachers of the subjects, not just diversity specialists, Ravitch says. She insists we need better-educated teachers and an end to secrecy about sensitivity: State education officials must put bias and sensitivity reviews on the Internet, listing the reasons that passages and test items were rejected.

Unsurprisingly, "The Language Police" has gotten the cold shoulder from our education establishment, which usually limits discussion to three topics: promoting diversity, reducing classroom size and increasing funding. Ravitch speaks for parents more concerned about something else: substituting censorship and propaganda for actual learning.