dry erase board on wheels. Under the premise of combining static analysis with dynamic analysis, based on the operating mechanism of modern market economy, comprehensive theories of economics, psychology and sociology , widely use modern scientific research methods, including economic statistics, Theories and methods of disciplines such as technical economics, marketing, statistics, operations research, probability theory and mathematical statistics, and project value assessment. And with the help of Microsoft Excel table calculation and other means to carry out research work. In the choice of methods, adhere to the principle of the unity of scientific and practical, normative research and empirical research.. The IQAio GR519 is an upgraded lightweight version based on the original IQAio GR511. The original dual-cavity structure was changed to a bottom-edge structure, so that the minimalist design accommodates modern classrooms and conference rooms. With one IQProjector V2 and one IQView E3821, you can achieve flexible and intelligent classroom.