First of all, the scum in the class refers to those who have poor academic performance and often make trouble in the class, but the people behind each class are always misunderstood as scum, because in the eyes of ordinary people, only those with poor academic performance will walk behind, and scum is generally not interested in learning.
Secondly, Xueba means to study well, behave well in class, listen to the teacher, and then have strong self-study ability and good exam results. Xueba usually sits in the front row or the middle row, and they can control themselves well in class and so on. If you say that a person is a schoolmaster, you must say that this person is very powerful!
Finally, learn from God. Speaking of learning gods, needless to say, this person certainly doesn't have to attend classes, and is as noisy as scum, but others can always get to the third place in the exam. This is a very talented person, but there are too few such people. It's good to have one or two in a class. Learning God can be said to be the existence that both schoolmasters and scum look forward to. After all, even if you are a tyrant, you need to learn, but learning God is different.
Generally speaking, learning God and learning hegemony is definitely better than learning scum, not discriminating against learning scum. This is just a synonym, everyone has their own way to go.