I'm so sorry comrades! I recently stopped updating for a month, mainly because I started working as a scientific research assistant in the Ph.D. research group from July 14. My Ph.D. supervisor asked me to exercise at least two hours a day and read a literature. In addition, my uncle’s family came to BJ recently for tourism. And next Monday, I will go on a business trip to Fujian and Jiangxi, and the elders in my family are not emotionally stable, so I can say that I have been very busy recently, so these days I can only say that I have updated it according to the situation. I have written more and more, I hope everyone will forgive me.