Write an application for exemption from examination, which will tell you how you have studied the same course before and how your grades are. Just apply for an exemption and ask for approval.
First of all, public courses can be exempted from examination, and English can also be exempted from examination after passing Band 4. The rest can't be exempted from the exam because you applied for two different majors.
The exempted courses are as follows:
Marx's Principles of Teaching Politicians
Introduction to Mao Zedong Thought
CET-4 (provided that you have passed CET-4 in college)
Before the exam, you must submit an application for exemption and a certificate that can prove that you have studied.