In the study of ancient China, how do historians divide up the time periods? * 1. By Mongol Invasions
2. The periods of time were given names of mythical Chinese dragons
3. According to the ruling Dynasty

Atherapist at a free university clinic treats elementary school children with behavior problems who are referred by a social service agency. she is also a doctoral candidate who proposes using data she has and will collect about the children for a case-based research project. describe the type of parental permission which is required in this case?