1.1 The Role and Content of Part Drawings.mp4+ 1.2 Orthographic Projection and the Formation of Three Views.mov+ 1.3 Projection Rules and Drawing Methods of Three-view Drawings.mov+ 2.1 Projection of Prisms.mov+ 2.2 Projection and Cutting of Cylinders.mov+ 2.3 The Composition Form of Composite Bodies.mov+ 3.1 Sectional View.mov+ 3.2 Section View.mov+ 4.1 Specified Drawing Methods for Threads .mov+ 5.1 Content of Assembly Drawings and Steps for Reading.mov+