没有合适的生长条件，树木就不能长得很高大。还有一些证据表明，在世界气候温暖的时候，尤其是在原本已经很温暖的环境里，树木的生长可能会放缓。

Without the right growing conditions, trees cannot get really big, and there is some evidence to suggest tree growth could slow in a warmer world, particularly in environments that are already warm.

youdao

从一方面来说，一个只有零星树木的世界与很多树木聚集成为森林的世界是不同的，但从另一方面来说，到底有没有一个界限，超过了多少树木，就可以称作是森林呢？

On the one hand, again, a world with scattered trees is different from one where they're collected into forests; but on the other, what exactly is a forest over and above its trees?

youdao

不幸的是，今天世界上很多地方人们没有意识到树木的重要性。

Unfortunately, nowadays in many parts of the world lots of people fail to realize the importance of trees.

youdao

没有了树木，我们整个世界都将会是一片非常干燥的大地。

Without trees our entire world would be a much drier place.

youdao

没有了树木，我们整个世界都将会是一片非常干燥的大地。

Without trees our entire world would be a much drier place.

youdao