Nitrogen guide education is quite good. There are too many institutions now, and the level of teachers in them is uneven. You should be careful when you report to the class. Did you buy counseling materials for nitrogen guide education when preparing for the exam? I also signed up for remedial classes. It is worth mentioning that the service is really in place. Usually, students have questions that they don't understand, and teachers will answer them seriously in the group. The course experience is very good.