What does the default course selection mean?

Referred to as pre-selection, first select the courses that must be selected or the courses that you like, and then the Academic Affairs Office will arrange, draw lots and kick out the personnel of each course according to the course selection situation of everyone. Pre-selection does not necessarily mean that you can attend classes, it's just your choice. There is a direct election after the pre-selection class, which is more important than the pre-selection.