Answer:
The phrase "whose selfishness had not hesitated to buy its own peace at the price, perhaps, of the existence of the whole human race" best supports the the that humans posses the ability to be monstrous. The phrase shows how humans are only thinking of what they want and need and not about how their voices affect the people and things around them.
The answer is the paragraph beginning..The MS control the tops.." tops of freight trains.." ..they rob migrants riding the trains.." In order to cross the country in search for her mother, Enrique has to go up against the most dangerous sitiations.Not only has he to cope with gangsters ,but also confront thieves and officers willing to hunt migrants .Nevertheless, after the abandonment that could have caused his addiction, Enrique decides that no action is dangerous enough to keep him away from his mother any longer.
7th grade would be middle school