Fill in the Blanks The earth riversOnline version Complete the definitions by Alejandro Castillo Martin 1 steep curves slowly river slowly lake flood rapidly deposited carried landscape stage deposits stage dragged river Source : the starting point of river . Upper source : the initial of the in the mountaints . The water flows and drags rocks with it . Middle course : where the flows more trought that are less , forming a plain . The mouth : at the final stage the water by the river , ot the sediments are . Lower course : in this final the river flows and the rocks that it has along with it and from called meander s