group of humans: any set of human beings

cargo ship: ship that carries cargo, goods, and materials onboard from one port to another

river: larger natural watercourse

Porto Velho: the capital of the Brazilian state of Rondônia, in the upper Amazon River basin

wharf: structure on the shore of a harbor or on the bank of a river or canal where ships dock

Madeira River: river in Bolivia and Brazil

worker: person who works

tram: public transport vehicle running on rails predominantly located on streets

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