What is the minimum time that a warm up should last?

Many1. why should teens be aware of health issues such as healthy sexuality, dealing with conflict, healthy decision making and cpr? 2. a) what are the 3 most important aspects/skills to learn in order to play volleyball activity well? b) explain how each aspect/skill is important when playing the game. c) describe 2 points of strategy you could use to you be successful at this activity.