1, ddl: a popular word in universities is called deadline, which means that deadline mainly refers to various tasks to be completed in universities.

2, the university catches up with ddl Generally speaking, during the university, there are many tasks or homework to be completed, such as ddl in the department, ddl in the class, and ddl in various professional courses. Because all kinds of ddl need to be completed, it also forms the form of catching up with ddl.