I don't recommend that you take the postgraduate exam at Harbin Institute of Technology. After all, Polytechnic University is partial to engineering, and mathematics must be tested in several subjects (the most difficult). Moreover, in recent years, graduate students of the University of Technology are very popular and have great competition. The most important thing is that there are only 280 points in the second interview of Polytechnic University (200 points for professional interview and 80 points for interview), so 500 points in the initial test account for a large proportion. Poor math will drag you down, while other subjects are not in our school, and professional courses will not be too good, and political English will not get points. Plus the retest score is small. To sum up, there is a great chance that you will not be admitted to the graduate school of science and technology university. I suggest you reconsider.