As rocks chip off mountains or break away into rivers, they make their way slowly downstream, eroding and breaking down into even smaller pieces as the water swirls the rocks around.

当岩石从山上掉下来或冲入河流时，它们缓慢地向下游移动，随着水带动岩石旋转，被侵蚀并分解成更小的碎片。