Fill in the Blanks continental waterOnline version continental water by claudia cuesta alonso 1 course River upper course course meanders middle mouth lower flow river Tributary are continously flowing currents os water that . are rivers that flows into another river . There are three stages in the course of a river : - The : the river flows slowly . I reaches the . - The : the river flows rapidly . It erodes rocks and creates river valleys . - The : the river flows less raidly and transports sand and stones . It creates bends called .