One species of tree replaces another as a forest ages.

随着森林老化，一种树会取代另一种树。

《柯林斯英汉双解大词典》

There is an apple tree in the forest.

森林里有一棵苹果树。

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A woodcutter was walking through the forest when a small tree called to him.

一个樵夫正穿过森林，这时一棵小树向他呼喊。

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It is at least worth noting, however, that forest people are not always the tree-huggers they are cracked up to be.

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Sino-Forest is a Wholly-Owned Foreign Enterprise that harvests, processes, and sells wood from leased or owned tree plantations in various Chinese provinces.

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The 3km and 9km Circles in a Forest trails explore the refreshing green environment, passing 3m-high tree ferns, old-growth trees, strange fungi and babbling brooks.

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