The construction of enormous hydroelectric dams along the river 's length has blocked its use as a shipping corridor to cities further upstream , but the economic impact of those dams offsets this .
DET NOUN ADP ADJ ADJ NOUN ADP DET NOUN PART NOUN AUX VERB PRON NOUN ADP DET NOUN NOUN ADP NOUN ADJ ADV , CCONJ DET ADJ NOUN ADP DET NOUN VERB DET .