20 years old here means 20 years old. We usually enter kindergarten at the age of 3 and go to primary school at the age of 6. Nine-year compulsory education (6 junior high schools), starting high school at the age of 65,438+05. After three years of high school, he took the college entrance examination at the age of 65,438+08 and entered higher education institutions. Generally, we study in university for four years. If you don't continue to take the postgraduate entrance examination, you will officially enter social work after graduation at the age of 24. Of course, except for some special ones, such as repeating classes or suspending classes, under normal circumstances, students spend their precious study career year by year according to this time.