Unit 4 Wheres my backpack?1. About the teaching materialThe main content of this unit is to talk about “Things around the house” and learn to inquiry “the location of objects”. Make Ss learn basic sentence patterns “Wheres my backpack? Its under the chair.” At the same time, guide Ss to adopt the studying strategies of listening for key words, inferring vocabulary and role playing to learn to use the preposition of place on, in, under, behind, next to express the location of objects.