水循环英文作文小学生【一】
最简单的而且能被生物直接利用的碳元素就是二氧化碳。二氧化碳在空中的含量为万分之三。它的来源主要是动植物的呼吸作用，细菌对动植物尸体的分解，及人类对矿物燃料的燃烧利用等。
二氧化碳和水经植物的光合作用生成生命中最简单的有机物：葡萄糖，并释放氧气。葡萄糖可以直接被动植物利用，经过呼吸作用重新分解成水和二氧化碳，并释放能量供它们利用。因此说植物既是二氧化碳的利用者，又是生产者，只不过利用大于生产罢了。那种说植物吸收二氧化碳制造氧气是不对的，因为它们同时也在释放二氧化碳。有了葡萄糖这种原始的.含碳有机物，植物再加上其它元素，就可以造出各种营养物质了，如蛋白质，脂肪（油）等。但无论是这些物质的结构多么复杂，最基本的东西还是碳。
二氧化碳被植物捕捉到并被储藏起来，动物吃了植物后经过分解吸收利用，再构建动物的身体组织，同时一部分又会被动物通过代谢生成二氧化碳和其它废物排到外界的环境中。这些废物又会被植物和微生物利用起来。动植物死亡以后，经过微生物的分解，变成能被植物利用的含碳物质，被植物的根吸收利用，与叶子光合作用生产的葡萄糖一起被储存到植物体内。微生物分解动植物尸体时也会放出一些二氧化碳到环境中。
一部分动植物的尸体还会被掩埋在地层下，与空气隔绝，经过数十万年甚至数亿年，形成化石类燃料：煤和石油。这些物质被你们人类开采出来进行利用，又变成生成二氧化碳，排到空气中。
值得注意的是自然界碳循环的过程是一个动态平衡。一旦这个平衡被打破，将会完成非常严重的后果。
近年来由于我们对煤和石油的过度开发和利用，另一方面又由于植物生长环境的恶化，造成空气中二氧化碳浓度增加。由于二氧化碳的分子量大于空气，就使得二氧化碳分布于地表周围，又由于它的密度大，就相当于在地表面盖上一层塑料薄膜，使得地球吸收的热量不宜扩散，这就是温室效应。
温室效应使得全球气候变暖，引发各种自然灾害，如干旱，洪水，两极冰山融化，海平面上升等。
我们要提倡低碳生活。少开一公里车，少用一张纸。虽然这些行为微不足道，但是只要我们一起行动起来，就可以减缓地球变暖的趋势，我们生存的环境就会有所改善。
水循环英文作文小学生【二】
When holiday comes, thousands of people pour into the tourist sites, they want to relax themselves and enjoy the beautiful scenery. But Chinese people have a bad habit, they like to leave some notes on the site, proving them have been here before. Such a behavior has been criticized by the public, because the leaving note will damage the preservation of the tourist site. Most of the tourist sites are part of our country's historical relics, these sites are priceless, it is everyone's duty to protect the sites. When we go to travel, we should behave ourselves. First, we need to have the idea that no rubbish being leaved behind when we leave the site. We should take away what we bring, keep the environment clean. Second, no any notes being written in the sites. Though in the old days, Chinese workers like to leave their names on the sites, but now it is a new world, we need to behave ourselves.
水循环英文作文小学生【三】
Christmas Day falls on the twenty-fifth of December.It is a very happy day for many boys and girls .Before the term ends in some schools ,the children act a nativity or “birth” play,showing how Jesus was born in a stable.
On the twenty-fourth of December,all children are very excited.Usually they are sent to bed early so that their parents can get the presents ready.The younger children think that Father Christmas will come down the chimney or fireplace ,so they hang up a sock for him to put presents in.The greedy ones even hang up a pillow-case or a sack to try to get more presents.Later that night,Father or Mother will put presents in the sock,and leave others at the side of the bed.
On Christmas morning,the children wake up very early.Some even turn on the light at two o'clock,and most of them are awake by six o'clock although it is not light in England for another hour or two at this time of the year.Children look for their presents,and the young ones play while the dinner is prepared.At about one o'clock in the afternoon,the Christmas dinner is brought in.The turkey or chicken is quickly eaten.Children search in their Christmas pudding for new coins which are hidden in it.The rest of the day is full of games and eating until the happiest of all Christmas hollidays comes to an end.
水循环英文作文小学生【四】
In recent years, tourism has been popular and played an important role in our nation’s economic growth. However, I am afraid that if tourism develops over, it will bring harm to the environment and give rise to many problems.
There are a few reasons accounting for my views and I would like to list three of them. One of the examples is that a large number of woods and other plants were replaced by all kinds of accommodation facilities or scenic spots. That definitely breaks the ecological balance of these areas and destroys the natural beauty of the scenic spots. Worse still, more pressure has been placed environment protection in that many tourists left their garbage in the scenic spots. In addition, over-developed tourism will occupy large numbers of farmland and lead to the shortage of the land.
In a word, tourism will be harmful to our environment if it is over development. Thus, I do not advocate that we development tourism without considering the environment. And we should keep the balance between tourism development and environment protection so that we can achieve the sustainable development between our nation’s economy and the environment.
水循环英文作文小学生【五】
Dear Santa Claus:
It is my great pleasure for me to write to you while the Christmas is approaching.Since I love you so deeply and trust you so sincerely ,you are always appearing in my dreams which make me excited and happy all the time.I believe that you are so kind-hearted with geat magics to the young kids and all the people as well.I am writing to you,telling you that the world nowadays are totally a mess!Wars,disputes,pullutions and many natural disasters are torturing the world and the people.It seems that the earth is coming to its end where the human being cannot live any longer.Sincerely wish that you can help us and the earth.
Sincerely,Yours
水循环英文作文小学生【六】
It has been two weeks since I last wrote to you. I am so sorry that I don‘t write you very often.
However, I have been busy with my preparation
for the final exams. As you know, I‘m coming home on Jan.14th. But before that, I have to take the final exams for all six classes I‘m taking this semester. Recently I have been in and out of the library a lot to do some research on the term paper for one of the classes. Most professors gave out the review problems already so that the students can study for the final. I think I‘m doing okay studying for the final.
Besides reviewing materials, I‘m also planning to host the New Year party of my department. You know there are so many talented people in my Communications major, but they picked me to host the party! Great, isn‘t it?
Well gotta go talk to you soon.
Love you,
XXX
