这句话选自那篇文章?We cool the air so that you don't have to run your

A Letter from a TreeDear human beings,I hesitated (犹豫) a lot before writing this letter。All I want to do is to ask you to have a look at your life。①But I’m not sure whether or not you’ll pay attention to me。(a)I’m a pretty old tree now:I’m 80 years old。So I’ve seen much of the world。We’ve lived on Earth with you for thousands of years。Each day we release (释放) oxygen and remove harmful gas so that you have pure (纯净的) air,we cool the air so that you don’t have to run your air conditioners all the time。② 我们有助于阻止地球上的土壤被冲走。And above all,we give all kinds of fruits,nuts,beans as well as wood to you。We like the world,we like you human beings,and we would do anything for you。But you’ve never been interested in us。③You hardly know anything about us。For example,did you know how amazing we are?Did you know that,just like you,we trees are communicating with one another all the time?And a tree can warn its neighbors of danger if insects attack it?And some of us pass nutrients (养分) and water around by joining our④______ together underground?I suppose (猜测) you didn’t。(b)⑤We are now in great danger because you are destroying us。You are,in fact,destroying (毁坏) us at a terrible speed。You are burning and cutting down millions of us each year,but you’re not planting enough。For every tree being planted today,30 trees are being cut down。What would you do if all of us died?Perhaps you would die,too。⑥_____ us,you wouldn’t get the ingredients (成分) for some of your important medicines,you wouldn’t have enough material for buildings,furniture,paper products,and your cities would look ugly。Moreover (此外),air pollution and noise pollution would become more and more serious,and your life would turn nasty (不舒服的)。。。Well,the list could go on forever,but I think I should stop。The best thing for you to do now is to stop your bad practices(行为)。Please stop (⑦a)______ us and start (⑦b)______ the environment,because we are the best fighters against pollution and we are your best friends!I wish all the best for you,and good luck!Your friend,An old tree