rail: linear bearing and guide elements used in rail transport

Amazon rainforest: large rainforest in South America

group of humans: any set of human beings

river: larger natural watercourse

swamp: a type of wetland

Abuna River: river in the Amazon region

Madeira River: river in Bolivia and Brazil

worker: person who works

railroad car: vehicle used for carrying cargo or passengers on rail transport system

railway: interconnected network of infrastructure and vehicles used for train rail transport