Fill in the Blanks ETAPAS DE LOS RIOSOnline version Completa las definiciones de las etapas de los rios by Alberto Pacetti Sánchez 1 initial carried slowy flows river stage slowy flows stage rocks river river final mountain river initial water final The source is the of the river . Upper course is the stage of the in the . Middle course is the where the more . Lower course is the stage and flows , it also deposit . The mouth is i the stage and the by the river into another .