南京航空航天大学的CAD制图教程，很适用，对新手来说它有许多方面的优点，使新手很容易掌握CAD制图的fangfa-Nanjing University of Aeronautics and Astronautics of the CAD drawing tutorial, it is applicable, on the green hand for it has lot of advantages, so that novices can easily master the CAD drawi

把CAD图纸转换为PDF，方便技术交流，在没装AutoCAD的电脑上也看CAD图纸。-Convert the CAD drawings into PDF, and facilitate technology exchange the computer without AutoCAD installed can see CAD drawings.