I am a master of maritime affairs in Dalian. This course is less difficult and the theory is relatively simple. I can get more than 120- 130 after reviewing for about two months. There are online classes now. If you take the postgraduate entrance examination, you can read textbooks, listen to online classes and review materials. The textbook only has about 100 pages of knowledge. If you take the postgraduate entrance examination, I suggest you take a look at the information and real questions.