The difficulty of approaching the college entrance examination. By reading the information of Chengdu Second Diagnostic Examination (202 1), we can see that the mathematics difficulty of Chengdu Second Diagnostic Examination (202 1) is close to that of college entrance examination, which increases the logic of basic knowledge and examines students' problem-solving ability. Usually, only students who have learned well enough can avoid the examination paper of Chengdu Second Diagnosis Examination.