求翻译：We konw that trees are very useful in our daily life.They gives us many things,suchu as wood,oxygen,rubber,medicines and many other things.They can aiso tell us a lot about climate,too.How?If you cut across a tree,you can see that it has many rings.Most trees grow one new ring every year.Because of this we know how old the tree is.If a tree is over a hundred years old,this means that it has over a hundred rings.When rhe climate is dry or very cold,treea do not groe very munch and their rings are usually thin.When it is wet ang good for trees,the rings are much thicker.If the rings are very thin or suddenly much thicker,this means that the climate changed suddenly.If we look at the rings on this tree,we can learn about the climate a hundred yeas age.We can see how the climate is changing today.是什么意思？

待解决 悬赏分：1 - 离问题结束还有