Many colleagues in our unit took part in the postgraduate entrance examination, and they all took the course of nitrogen introduction education. The landing rate of his home is still quite high. The lecturer who teaches nitrogen is very responsible to the students. Basically, it's a day's class, and there are also supporting online classes. They can also communicate face-to-face with lecturers at home at any time, which is of great help to the students. I am also a beneficiary of his family. .