Among the four research methods in this paper, the most difficult part is probably methodology. Methodology is to describe the specific methods and means used in the research process and how to collect and analyze data. It involves the detailed description of research design, including experiment, investigation, observation, data collection and analysis.

Methodology writing needs a deep understanding and clear thinking of research methods and processes to ensure the reliability and effectiveness of research. Methodology also needs to consider the limitations and limitations of the research and explain how these factors affect the research results. Therefore, methodology is one of the most important and challenging parts of the paper, which requires a lot of energy and time to write and improve.