In Brazil, Bolivia and Peru most of the people make their livings through

Much of the natural habitat of the region remains intact, protected by sheer inaccessibility. People have dwelled along the major rivers for millennia and have subtly altered the forests on a small scale but around the urban centers development proceeds. Very few roads exist in the region, limiting development. Intense deforestation is constrained to the few roads that do exist or around urban centers such as Iquitos, Puerto Maldonado, and Rio Branco.

Explanation: