Green fruit system is an educational management platform, in which teachers can enter students' grades and make corrections. According to the instruction of qingguo system, teachers can input, modify and query students' grades in the system. Therefore, the teacher of qingguo system can change his grades.

Although the teacher of Qingguo system can correct the grades, it should be noted that the grades should be based on objective facts and cannot be tampered with at will.