Generally speaking, 20-30 hours of public subjects study every year is an important basis for job title declaration and job promotion. What you want to learn is different in every region, nothing more than watching videos and taking exams.

I didn't study the compulsory subjects of public courses in previous years, so I can usually make up for them. Of course, it depends on each specific situation. If the government does not open make-up schools in strict accordance with the actual situation, there is no way out. The study of public subjects is so important that it is best not to miss it, otherwise it will seriously affect the professional title declaration and post appointment and promotion of professional and technical personnel in that year.