The formation of arch effects will bring the sand filling over the region of deep concavity hindered and the degree of compaction of molding sand at the deep concavity reduced.
它的形成会阻碍型砂向深凹区的填充，使得深凹处砂型紧实度降低。
2
After one more hours, at 3 clock and half, we arrived the end of this road - Sand Dune Arch Trailhead park place!