相信备考托福的同学都知道托福TPO的重要性，为了方便大家备考，下面小编给大家整理出托福TPO1阅读真题原文及答案翻译，希望大家喜欢。
托福TPO1阅读真题原文Part3
Timberline Vegetation on Mountains
The transition from forest to treeless tundra on a mountain slope is often a dramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.
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