Sending a paper to a foreign school for review is called external review. There are two cases of external audit. One is that the degree office of our graduate school sends the papers to teachers of other schools for review, and the other is that the papers are sent to the State Council degree office, which sends them to other schools for review. The former is a real-name external trial, and the latter is what we often call blind trial. Before this summary is submitted for review, the paper should be processed, that is, the names of students, tutors and authors who published their own papers should be hidden.