Meanwhile, Brazil has employed 8,700 military personnel to fight illegal_________ along its northern borders.

With a population of some 19 million, _______ is the largest city in the Southern Hemisphere.

Because miners use _________ and other toxic compounds to separate gold from ore, high levels of ________ and cyanide pollution in rivers have been reported.

A Rain forests harbor at least _______ of all animal and plant species on Earth.

 In response to the high rate of deforestation in _________, the country’s government passed the Zero Deforestation Law in 2004.

 In Peru, for example, tens of thousands of people have set up camp in the Amazon rain forest in search of vast ______ reserves.

 The primary cause of ________ is not drought, but rather mismanagement of land by human activities such as overgrazing of livestock and deforestation.

___________, the growth of a single type of crop on agricultural or forested land, depletes the soil of its nutrients.

 Certain soil types in South America—such as the volcanic soils and _______ found in the humid tropical lowlands—are especially vulnerable to erosion.