大单小单大双小双公式

简介：Su Can stayed here for a while, and then went back to the classroom where he used to be a senior high school student. The door of the light green classroom was closed tightly, and he could only see the scene inside through the window. The blackboard was clean without any graffiti, and Cheng Keshu was nowhere to be found. The homework assigned every day was left behind, and the labor committee member wrote the name of the person who arranged the sanitation duty in the corner.