There are three subjects in the preliminary examination of mathematics, namely advanced mathematics, probability theory and mathematical statistics, and linear algebra. Probability theory and mathematical statistics Mathematics II is less than Mathematics I..
If you want to transfer to Mathematics One, you can first consider your own learning foundation of probability theory and mathematical statistics. There are still some difficulties, that is, math I will be a little more difficult, but this is not absolute. Some people think that the second difficulty in mathematics is mainly related to their review level, and they also analyze it according to their own situation.