I wonder if you are from USA or not.In China now,especially among younger generations,a US TV play called<Prison Break>is extremely popular here.In the latest episode of Season II,in order to save his brother Lincon Burrows,the protagonist Michael Scofield asked a teenage boy called Chaco to help him to find a notorious drug dealer.Today I googled this word"Chaco" and learned the following:The Gran Chaco (Quechua chaqu, "hunting land"), dubbed by some as "the last South American frontier", is a sparsely populated, hot and semi-arid lowland region of the Río de la Plata basin, divided between Bolivia, Paraguay and Argentina".
Interesting I think.