In recent years, mathematics is mainly about testing basic knowledge. If you have a poor foundation, but you are only a junior now, you can read through your textbook Advanced Mathematics first. It should be from Higher Education Press, and it is better to find the fourth edition. You should use the fifth edition now and try to borrow the fourth edition. That's good! Do an after-class exercise every time you read a lesson and repeat it twice. If you look carefully, the basic guarantee of high numbers is no problem.
In the postgraduate entrance examination, the proportion of high numbers is not small, and it is not difficult. You should take it off!
Come on! Work hard from now on!