1.Their villages were little more than clusters of thatched huts.
2.When local resources became depleted， the tribe moved on.
3.To causal observers， as well as to influential natural scientists and regional planners， the luxuriant forests of Amazonia seem ageless， unconquerable， a habitat totally hostile to human civilization.
4.The popular conception of Amazonia and its native residents would be enormously consequential if it were true.
5.Investigators who argue otherwise have unwittingly projected the present onto the past.
6.The evidence for a revised view of Amazonia will take many people by surprise.
7.The realization comes none too soon.
8.Ironically， one major casualty of that extreme position has been the environment itself.
9.The long-buried past， it seems， offers hope for the future.