Let students know that this section focuses on changes common to both boys and girls during puberty.
Conduct Activity 2-1: How Tall? Make sure students focus on the concept that there is a wide range that is considered normal for development.
Have students read the material on weight. Stress that weight has an even wider range of normal than height, because part of weight gain depends on diet and exercise, factors over which individuals have some control.
Point out that muscle development is one area in which there are more differences physiologically between boys and girls. However, also point out that an individual boy or girl can be stronger than another based on their level of physical fitness.
Acne is a topic about which many students are especially interested. You may ask them to discuss their own methods of trying to deal with acne and the information in the text, in an attempt to clarify what will and what will not work to control this condition.