"Sinking podium"@en . . "Some sink and rise up again in the river repeatedly, while some move up and down or side to side. Some even flow in one direction in a single file line continuously until they reach the end and sink."@en . . . . "Some sink and rise up again in the river repeatedly, while some move up and down or side to side. Some even flow in one direction in a single file line continuously until they reach the end and sink."@en . .