进一退二法倍投法优缺点

简介：The first cafeteria and the second cafeteria are on the left side of the teaching building. Straight ahead from the three teaching buildings is the marble square, which is usually used for opening ceremonies or small-scale lectures and meetings for the whole grade. Su Can walked with the dark crowd and separated when he reached the Marble Square. He went down the fifty steps and went straight to the gate of No. 2 Middle School.