共享音频

UNIT 2: THE BONES OF THE BUILDING (STRUCTURES - COLUMNS & BEAMS) INTRODUCTION A building has a skeleton. We call it the structure. The structure holds everything up. The two most important parts are columns and beams. STORY 1: What is a Structure? Think about your body. You have bones. They give you shape and hold you up. A building has a structure. The structure is the frame. It can be made of wood, steel, or concrete. The structure carries all the weight. It carries the weight of the roof, the