Write it in the introduction of the text. The research status at home and abroad should be written at the beginning of the paper, which is the theoretical basis of the whole paper. When writing your graduation thesis, briefly describe the beginning, development and main direction of the research. The most important thing is to outline some current main viewpoints of the research, and indicate the representative author and the year when the opinions were published. Furthermore, simply write a summary of the research status at home and abroad, which is divided into technical deficiency and research deficiency.