SACRAMENTO (AP) - State Sen. Sheila Kuehl says a key aspect of history is missing from school textbooks - the contributions that homosexuals have made to California and the nation. Kuehl, D-Santa Monica, has introduced a bill that would fill that void by requiring textbooks and other social science materials to discuss contributions that gays, lesbians, bisexuals and transgender people have made to the state and nation's economy, politics and society. The bill also would prohibit textbooks from criticizing people because of their sexual orientation. Current law sets that standard for discussions of race, color, religion, national origin, ancestry, gender...