Post 90's open sexual behavior, immature sex concept. Since she began to teach, Ms. Lu has been doing students' puberty education positively. "In fact, many head teachers have been doing sex education, but under the name of moral education, which is not so regular." Ms. Lu helps students solve any confusion during puberty. For 13 years, students who consulted her have changed from post 80's to post 90's. Elders all say children of post 80's are more self-centered and difficult to discipline. Ms. Lu said helplessly......