Trees do more than keep the soil in place. They also soak up water and prevent flash floods, and keep rivers clear of sediment that can kill fish.

树木所起的作用不止于保持水土。树木还吸收水份、防止洪水突发，并使河流不至于含有可杀死鱼类的泥沙沉淀。

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Haiti's trees and roots used to keep the mountainous island's soil in place.

海地的树木和树根过去使这个多山岛国的土壤稳固。

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Trees keep moisture in the ground by holding the soil in place to protect erosion.

树木固定土壤，防止侵蚀，从而保持地里的水分。

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