我们必须种树的原因是它们能供应给我们新鲜的空气。
The reason why we have to grow trees is that they can provide us with fresh air.
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全世界都知道树木对我们是不可或缺的。
It is universally acknowledged that trees are indispensable to us.
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我们再怎么强调保护树木的重要性也不为过。
We cannot emphasize the importance of protecting trees too much.
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保护树木可以使环境可持续发展。
Protecting trees enables the environment to develop sustainably.
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我们应该不遗余力地美化我们的环境。
We should spare no effort to beautify our environment.
Zebe
保护环境，人人有责。