As for the reasons for the failure of the exam, there are many reasons, for example, the tension in the exam leads to inattention; The foundation is not solid, leading to failure in the exam; My usual habits are not good enough, so I can't carefully examine the questions and answer the questions in the exam.
Solution: (1) Believe in yourself and overcome the exam tension. (2) carefully examine the questions and answer them seriously. Pay attention to starting from the usual homework.
I hope it helps you. Finally, I wish you progress in your study!