有关环境英语作文热门19篇

假如你是李华，现任你们学校的学生会主席。你将代表学生会起草一份倡议书，号召全校同学行动起来，为环保运动做出自己的努力。同时下周六学校将组织同学在全市进行环保宣传活动，征召志愿者到校学生会报名。

注意：(1)短文应该包括以上所提供的主要信息，可适当发挥;(2)词数：120左右;(3)倡议书格式以提供，不计入总词数;(4)参考词汇：征召(新人) recruit。

15 May, 2010

Dear brothers and sisters,

____________________________________________________________________

____________________________________________________________________

Yours sincerely,

Li Hua

【参考范文】

15 May, 2010

Dear brothers and sisters,

On behalf of the University Students Union, I, the Chairman of the Union , am earnestly calling for your active participation in our environmental protection campaign. It is the duty of every global villager; man just can not sustain his glorious civilization without a rewarding environment, which will be possible only if man makes considerable efforts to protect the environment.

Do you cherish precio us opportunities to volunteer in our joint efforts in environmental protection? Here is a great one not to be missed by any enthusiastic youth; Right next Saturday, our university is to run a publicity campaign to advocate environmental protection across the city. The University Students Union will be in charge of recruitment of volunteers. Lets join our hands and take action immediately.

Yours sincerely,

Li Hua

Everyone can do something for our environment. For me, I should try to save electricity in my daily life. For example, if I am the last person leave the classroom in the evening, I will always remember to turn off the lights. In order to protect our forests, I will use paper wisely. I should try to use both sides of paper whenever it is possible. I will not use things like paper cups and disposable chopsticks because they are made of wood. I believe that doing all these small things will improve our environment and help make our world a better place to live in.

In fact, there are many things that can seriously pollute the environment: litter, spitting, grass and so on. The consequences are severe. But the waste of resources cannot be ignored. The worst is the waste of water.

At present, the reform and development of our country is at a critical juncture, and we should strive to achieve the goal of building a moderately prosperous society in all respects. But there are still some problems -- our living environment is seriously polluted; And the green resources are falling.

We do a lot of what the environment, such as: on one occasion, in a clean small garden, there have been some rubbish, gradually where there are a lot of people throw garbage, there is a garbage dump. It turned out that the trees were green and the flowers and grass were blooming. The bees and the butterflies were there, and there was a smell of enchantment. But now, there was nothing to do with it, and the smell of it was so bad that no one was willing to stay there any longer. Alas! It is a pity that such a beautiful garden is gone. If people notice that they dont pollute the environment, now, by the way, its a kind of escape. And, what a wonderful thing for people to have a rest and take advantage of the cold. But now its a junkyard, and the consequences of polluting the environment are terrible.

And there are a lot of factory waste is also pollute the environment, but the most serious is the pollution of water, I heard of such a story: there was a village, there was a clear pool. There were lotus flowers in the water and the goldfish, and it was so beautiful that visitors to the village would not forget to take a look at the scene. And people in the village wash and cook and drink water and water, so the water is very precious. One day, a businessman opened a factory near the pond, and the factory shut down a lot of waste water and garbage and went into the pond... The result can be imagined: the goldfish died, the water side became the sewage, the tourists no longer came, the people in the village moved away... Alas! The little pond has disappeared. The factory severely polluted the environment and made the environment in the village very bad and affected peoples lives. Its a story, but there are a lot of these things in everyday life, and the results are very serious, not just simple consequences.

In fact, there are many things that can seriously pollute the environment: litter, spitting, grass and so on. The consequences are severe. But the waste of resources cannot be ignored. The worst is the waste of water.

Now, Beijing is a city of severe water shortages, but there are a lot of people in the waste water, such as: there are a lot of people out of the water to wash the dishes and laundry water and reuse. In fact, although can only save a little water, economy is a lot of!

Also, people who sell fish in the market love to put a faucet on the side of the water, and when they use water, they will let the water flow freely. How much water they would waste if they went on like this!

The drink, the wine, etc., are now made with water. Some factories use a lot of water, so some of the water is wasted. Thats a lot of wasted water. This water can do a lot if you save it! You can also avoid a little water.

[保护环境的英语作文模板

, hello! I am an alien from mercury. This time, I wrote to you for the environment on earth.

Ago, I went to visit the earth, the earths beautiful scenery let me fascinated. The river clear visible bottom, can see the fish swimming around, can see the bottom of the river green brown stone. A stream of bright blue, let me deeply respected. Come to the garden, and flowers there. Came to the forest, where birds, the animals free life. Lush trees... Returning to mercury, I told my friends everything I saw on earth, ready to go to earth for a few years with my friends.

A few years later, I came to earth with the guys. At this time, we cant believe the scene appeared in front of us: once lush trees has been changed to dongdong tall buildings. The previous clear visible bottom stream and stream of bright blue, has disappeared, has become a stinking creek, before swimming fish have been stinks, have a lot of rubbish in the river. Looked up and saw the sky is gray, it is already lost before the beautiful beautiful blue skirt. Road piled up a lot of rubbish, everyone passing by, and no one to clean up the trash.

I want you to take care of the environment and protect the environment.

Good environment can make people feel happy and fit . To improve the environment means to improve our life.

好的环境能让人感到快乐和健康。为了改善环境的手段来改善我们的生活。

We should plant more trees and flowers around us . We shouldn’t cut them down . We should stop factories from pouring waste water into the river and waste gas into the air.

我们应该在我们周围种植更多的树木和鲜花。我们不应该削减下来。我们应该阻止工厂向河里倾倒废水和废气到空气。

Whenever we see litter on the ground , we should pick it up and throw it into dusbins. Never spit in public. Don’t draw on public walls. It’s our duty to protect the environment.

当我们看到垃圾在地上，我们应该把它捡起来，把它扔进垃圾箱。不要在公共场所吐痰。不要在公共场所的墙上画画。保护环境是我们的职责。

Nowadays, the environmental protection is becoming one of the most important issues in the world. Being one of the members of our society, what shall we do to protect the environment

First, stop using plastic bags, boxes and bottles. Stores should be required to use the bags, boxes and bottles which are made from paper. Secondly, more and more trees and flowers should be planted to keep our surrounding clean. People must be required to plant plants around their houses and work places.

Finally, we must control the pollution by law, according to which, polluted water and air exhausted from factories should be forbidden.

These are some of the measures that we can take to protect our environment and they are not hard tasks for us. Remember, the earth is the only planet we could live at present.

Since the first day, BNBM has paid more attention to protect the environment as its social responsibility, by developing green building materials, producing green products and creating green enterprise. According to the spirit of "From the nature, for the nature and return to the mature", BNBM has tried its best in developing new technology and improving equipment to reduce the pollution.

With the improvement of peoples living standard, people more and more do not take the protection of the environment, throw rubbish everywhere and spit everywhere.

Whenever I see garbage on the ground, I will be deeply touched, protect the environment, starts from me. Take the a small river near my house, for instance, in the past, the water in the river is very clear, like a bright mirror, can see clearly the many stone in the river; You can see fish free in swimming in the river. There are often many children playing, playing in the river water; The adults in the river to wash the dishes, washing clothes. Gradually, people then throw the garbage into the river, sewage discharge into the river, make the river as well as smelly and dirty, can no longer on the bottom, into a murky waters of the bin. Serious environmental pollution, serious harm peoples health. Yes, only set up the idea of protecting the environment, have a better tomorrow.

On Sunday, I find to my good friend small good, each with a plastic bag, pick up the trash in the river one by one to light, our hands are full of bags, is really "to eat"! Even if we pick up the trash in the river, but you cant stop the garbage in the river, get off there will be, how to do? The most critical or arouse peoples environmental consciousness, we took a plank on the plate is greatly write: please protect the environment, starts from me. We put it in the river, in a prominent place in the task is complete, we are pleased to go home.

In order to protect our own home, in order to protect our own life, for the sake of our own future, in order to our beautiful environment, make the sky bluer, the water cleaner, let mother earth more lovely and more vibrant, let us open hands, a love, out of a force, creating a green environment.

随着人们生活水平的提高，人们越来越不重视保护环境，随地扔垃圾，随地吐痰。

每当我看到地上的垃圾，我就会感慨万千，保护环境，从我做起。就拿我家附近的一条小河来说吧，以前，河里的水十分清澈，像一块明亮的大镜子，可以清清楚楚地看到河底的许多石头;可以看到小鱼在河里自由自在在游来游去。经常有许多小朋友在河里嬉戏、玩水;大人们在河里洗菜，洗衣服。渐渐的，人们于是把垃圾扔到河里，污水排放到河里，使河水变得又臭又脏，再也不能清澈见底，变成了浑浊不清的垃圾箱。严重污染环境，严重危害了人们的身体健康。对，只有树立保护环境的观念，才有美好的明天。

星期天，我找来我的好朋友小好，每人拿一个塑料袋，把河边的垃圾一一捡光了，我们手里都是满满的一塑料袋，真是“满载而归”啊!即使我们把河边的垃圾捡光了，但是河里的垃圾是阻止不了，捞掉了还会有，怎么办好呢?最关键的还是唤起人们的环保意识，我们找来一块木板在板上大大地写上：请保护环境，从我做起。我们把它放在河边最显眼的地方，任务完成，我们高兴地回家了。

为了保护我们自己的家园，为了保护我们自己的生命，为了我们自己的将来，为了我们美好的环境，让蓝天更蓝，让清水更清，让地球妈妈更可爱，更生机勃勃，让我们张开小手，献一份爱，出一份力，共创绿色的环境。

How to protect our environment

We all know it is becoming more and more important to protect our environment well.We should stop cutting down trees ,dropping litter everywhere and throwing waste before it is processed. It has caused lots of problems such as much rich land becomes desert;Rivers become dirty ;The air is becoming worse and worse ;The temperature is becoming hotter and hotter.So we must do something to change the situation.Wed better walk or ride bikes to work or go to school instead of driving a car,We mustnt use plastic bags.Our government must take some measures to prevent factories producing smoking etc.

[关于环境污染的大学英语作文

There have been many environmental protection problems in recent years . One of the most serious problem is greenhouse gas emissions have caused climate change ,At the same time ,lots of trees have been used and wasted.So our earth is becoming warmer and warmer . .That brings us illnesses and death.

Luckily ，,many countries have done a lot to stop environmental pollution。Its the most important in the environmental protection today.

In my opinion ,on the one hand ,through education we should make people realize that destroying the environment means destroying ourselves,..On the other hand ,we should try to do something to produce fewer greenhouse gas emissions.

In a word .we must develop low-carbon economy

现在这些年已经有很多关于保护环境的问题。其中最严重的一个问题就是温室气体排放已经造成了气候改变。同时，很多树木被砍伐掉了，而且大量别的资源已经被用完或者浪费。所以我们的地球变得越来越温暖(热)。这样带给我们的是疾病和死亡。。

幸运的是，很多国家已经采取了很多措施来控制环境污染问题。如今，这是最重要保护环境的措施。

我认为，一方面，虽然教育我们应该让人们意识到破坏环境就是伤害人类自己。另一方面，我们应该尽力做一些事情来控制温室气体增长。

总之，我们必须发展低碳经济。

What is my ideal? This question has been in my mind for a long time. Well, everyone will laugh and say that I just want to be a security guard.

If you dont believe me, I am a small officer who cant reach the 14 products, but if you dont believe me, please listen to me.

Our community is famous for "thieves". I used to have a very good bike, because I didnt have a lock, so I had to stop in the small village. The next day I woke up to the garage, and my car didnt even have a shadow. At first I thought my mother was riding, and then I asked, it was stolen. Another time, we were not at home, the thief even climbed into our house and stole over 500 yuan!

The madness of the thief has made it impossible for the inhabitants to live in peace, so I resolved that I must defend our community when I grow up. I promise you that I alone will never let anyone who destroys the community get away with a precious thing.

Although this position is small, but without security, our homeland will not be peaceful and harmonious.

[理想工作环境英语作文

The environment has been polluted badly today and the nature punishes the

human being by all kinds of disasters, such as the heavy haze in Beijing, which

damages people’s health. World Environment Day is on June 5th. It pays attention

to call for the public to make an effort to bring the world a clean

environment.

Look at the pollution around us, which exists everywhere. The cars release

the gas which pollutes the air and the rubbish can be found in every corner of

the street. All of these daily incidents hurts the world we live. Especially the

factories, they release the heavy smoke and make the sky becomes dark. What’s

more, the wasted water flows to the clean river.

Though the government has made some action to punish the businessmen for

releasing the polluted sources, they still dare to take the risk of earning the

biggest profit. If we hurt the environment, it will hurt ourselves, because we

live together. The polluted environment threatens our health. If we want to live

the comfortable life, then the only way is to be nice to the environment.

Some people believe that the Earth is beingharmed(damaged) by human activity。 Others feel that human activitymakesthe Earth a better place to live。 What is your opinion?Usespecific reasons and examples to supportyouranswer。

People have been living on the Earth for thousands of years。Humanactivity influences the Earth。 Some people believe that theEarth isbeing harmed by human activity。 Others feel that humanactivitymakes the Earth a better place to live。 In my opinion， theearth isbeing damaged by human activity。 There are manystatementssupporting my opinion。

Human activity has damaged natural environment and almostexaustednatural resources。 Modern industry needs more and moreresources，including minerals， fuels and water。 So we confront ofthe seriousproblems such as the lack of fuels and water。Ecological balance isdamaged because factories occupy many placeswhere animals andplants live。 More and more buildings areconstructed and forestsbecome less and less。 If we cannotrecognize these problems andsolve them soon， we would finally losethe environment suitable forour living。 An other serious problem is the green-house effect。

Humanactivity decreases forests and increases the usage of fuels sothatthe gas of carbon dioxide is output more and more and there arenotenough plants to absorb it。 The green-house effect is moreobviousand more sensible these years。 Due to the effect， icebergsin thesouth polar and north polar melt and the sea level becomeshigherthan before。 I am worried about the cities nearby the sea andhopescientists find an effective method to eliminate thegreen-houseeffect。 Although we have advanced machines and our life seemsmorecomfortable than before， we have less chances to approachnaturesand less spaces to act。 The cities become bigger and if wewant tohave a picnic with our friends， we have to drive a longdistance tofind a natural place。 In fact， the spaces of humanactivity arebeing damaged by the skyscrapers and factories。 From the above statements， we can conclude that humanactivitybrings the Earth many damages。 Fortunately people haverecognizedthe point and I believe that the Earth will become abetter placeto live with our ceaseless efforts。

[英语作文：人类活动破坏了环境

假如你是新华中学的学生，名叫MIKE。去年6月1日，我国已经禁止使用塑料袋，你对此有何看法和什么好的建议？

I’m Mike. I am a student in Huaxing Middle School. Do you know the plastic bags? Do you often use the plastic bags? I don’t like them. I think they use the wasting valuable oil their production. And they can’t decompose(分解) in a short time. The plastic bags will make our world worse. I agree with the rule, which people can’t get the free plastic bags in the shops, supermarkets. It encourages people to use their cloth bags and baskets. It’s good for our environment.

So I hope all the students in our class stop to use the plastic bags, and use our own cloth bags. I hope we can take care of our environment.

Let’s make our world more and more beautiful.

我是迈克。我是新华中学的学生。你知道塑料袋吗？你经常用塑料袋吗？我不喜欢他们。我想他们用的是浪费宝贵的石油生产。他们不能分解（分解）在很短的时间。塑料袋会使我们的世界变得更糟。我同意这一规定，在商店、超市里，人们无法得到免费的塑料袋。它鼓励人们用自己的布袋和篮子。这对我们的环境有好处。

所以我希望我们班的所有同学都停止使用塑料袋，并用自己的布袋。我希望我们能照顾我们的环境。

让我们让我们的世界变得越来越美丽。

[关于环境保护问题的英语作文

There are two main causes for cancer: heredity and environment. We can do nothing to change our heredity, that is, the basic physical characteristics that arepassed on to us by our parents. However, we can do a great deal to control our environment, which may account for eighty to ninety percent of all cancers.

Enviromnental pollution can be divided into two kinds: personal and impersonal. Personal pollution may be defined roughly as unhealthy habits such as smoking, drinking, and eating the wrong foods. Clearly, with enough will power we can control this personal environment.

Impersonal pollution, on the other hand, refers to those things which are beyond our individual control. One example would be indus trial pollution, which is very hard to control because of the expenses that are needed. The American automobile industry, for example, resisted the law requiring smog-control devices because il feared the added expense would reduce profits. Nevertheless, some laws protecting the environment have been quite successful in reducing pollution.

[关于癌症与环境的英语作文

Once man did not have to think about the protection of his environment.There were few people on the earth, and natural resources seemed to be unlimited.

Today things are different.The world has become too crowded.We are using up our natural resources,and polluting our environment with dangerous chemicals.If we continue to do this, human life on earth will not survive.

We realize that if too many fish are taken from the sea, there will soon be none left.Yet,with modern fishing methods, more and more fish are caught.We know that if too many trees are cut down, forests will disappear.Yet, we continue to use powerful machines to cut down more and more trees.We see that if rivers are polluted with waste products, we will die.Yet, waste products are still put into rivers.

We know that if the population continues to rise at the present rate, in a few years, there wont be enough food.What can we do to solve these problems?

If we eat more vegetables and less meat, there will be more food available.Land for crops feeds five times more people than land where animals are kept.

Our natural resources will last longer if we learn to recycie them.

The world population will not rise so quickly if people use modern methods of birth control.

Finally, if we educate people to think about the problems we shall have a better and cleaner planet in the future.

Tourism is becoming increasingly important to many countries but it also has its disadvantages.What are some of the problems of tourism?

First of all,tourism can ruin the environment.Another aspect is cultural,as sometimes foreigners show no respect for national traditions.In addition,it causes the price of everything rising.

In a word,tourism is very important,there are a lot of advantages about it,but we also should remember that there are always two sides of everything,but I believe the advantages and disadvantages of tourism can be in balance if we all become more attentive to each other and the world around us.

With the improvement of our living standard, more and more people can afford a car. As a result, our roads are more often than not crammed with cars. However, with more and more waste gas being discharged by the cars, the problem of air pollution becomes even more serious. So nowadays we advocate to lead a low-carbon life.

随着人们生活水平的提高，越来越多的人能买得起一辆车。作为一个结果，我们的道路上挤满了车。然而，随着越来越多的汽车废气排放，空气污染问题变得更加严重。所以现在我们提倡低碳生活。

My suggestion is we should ride bikes more often instead of driving cars.By riding a bike, we can not only exercise our body but also protect our environment. Why not have a try, my dear friends?

我的建议是我们应该更经常骑自行车而不是汽车。骑一辆自行车，我们不仅能锻炼身体，也能保护我们的环境。为什么不试一试，我亲爱的朋友?

There are still many problems of environmental protection in recent years。 One of the most serious problems is the serious pollution of air， water and soil。 the polluted air does great harm to people’s health。 The polluted water causes diseases and death。 What is more， vegetation had been greatly reduced with the rapid growth of modern cities。

To protect the environment， governments of many countries have done a lot。 Legislative steps have been introduced to control air pollution， to protect the forest and sea resources and to stop any environmental pollution。 Therefore， governments are playing the most important role in the environmental protection today。

In my opinion， to protect environment， the government must take even more concrete measures。 First， it should let people fully realize the importance of environmental protection through education。 Second， much more efforts should be made to put the population planning policy into practice， because more people means more people means more pollution。 Finally， those who destroy the environment intentionally should be severely punished。 We should let them know that destroying environment means destroying mankind themselves。

目前环保还存在着许多问题。最严重的问题就是空气、水和土壤的严重污染。污染的空气对人类的健康十分有害。污染的水引起疼病，造成死亡。更有甚者，随着现代社会的迅速扩建，植被大大的减少。

为了保护环境，各国政府做了超多的工作。采用了立法措施控制大气污染，保护森林资源和海洋资源，制止任何环境污染。因此，在当今的环保中政府起着最重要的作用。

我的看法是，为了保护环境，政府应当采取更具体的措施。首先，应当透过教育的方法使人们充分謒到环境保护的重要性。第二，应更加努力把计划生育政策付诸实施，因为人口多就意味着污染严重。最后，要严惩那些故意破坏环境者。使他们破坏环境就是毁灭人类自我。

[英语作文保护环境的

Our beautiful earth is only one, is also the only one. If you dont cherish, in the end, the only regret. But now, people regardless of the image, the damage to the environment.

In the street, always see someone to walk less, will their garbage on the ground, this kind of behavior is damage to the environment, and not beautiful. Although there is a punishment, but has no effect. In the end, only the cleaner to clean up the mess. That if be in their own homes, garbage, flies are flying everywhere, do you feel better? That if no cleaner in the world, if so do you dare to imagine? Looking at people such behavior, the earth mother cry. Lets ensure that their hand, whether in where, what time, please send their garbage home.

There is a bad behavior, and that is the grass. Every time after school, some children for fun, always likes to play football on the grass. When your foot jump on it, when enjoying the care of the earth, you can know it in complains to heaven. The grass also hurts, it just didnt express. Dew on the grass face every morning there will be some, and the dew like their tears. The grass also have feelings, when it is happy, it will be a purposeful, enjoy the warmth of sunshine, the breeze bath; When it cry, it will be bent her waist; When it is complained that their is a humble grass, it dead. Lets ensure that their feet, dont trample on the lawn. Use action to soothe the soul of the dead, renewed the miracle of life.

Have you seen? Dozens of people saw an axe in hand, they are going to cut down trees. When forests there saw, with the trees fall. When there is a tornado and sandstorms, no trees to shelter from the rain. Then there is no regret medicine to eat. Without trees, also become no longer pure and fresh air. When youre cold, you go to pick up trees make a fire, it is the warmth of your sacrifices for a tree. Some trees grow hundreds or even thousands of years, is a humble axe ended its long life. What a strong tree, I do not know the moment when it fell, it think about? How hardy tree, can eventually escapes according to the bad luck.

Friends, protect our environment, is to protect our earth. Cherish our only the earth, is to cherish our life. When a rainbow sky, means that garbage to go home, the grass smiles, uncle grandpa happy, our earth mother without crying.

参考翻译：

我们美丽的地球只有一个，也是唯一的一个。如果不好好珍惜，到头来，只有后悔。可现在，总有人不顾形象，在破坏环境。

在街上，总会看见有人为了少走几步路，将自己手中的垃圾随意扔在地上，这种行为既破坏环境，又不美观。虽然有惩罚，但一直以来并没有什么成效。到最后，只有清洁工来收拾残局。那假如是在自己的家里，到处都是垃圾、苍蝇还满天飞，你自己好过吗?那假如世界上没有清洁工，要是这样下去你敢想象吗?看着人们这样的行为，地球妈妈哭泣了。让我们管好自己的手，不管是在什么地方，什么时间，请将自己手中的垃圾送回家。

还有一种不好的行为，那就是践踏草坪。每当放学，有些孩子为了开心，总喜欢在草地上踢足球。当你的脚踏在上面蹦蹦跳跳的时候，享受大地关怀的时候，你可知道它在埋怨上天。小草也会疼，它只不过没有表达出来而已。每天早上小草脸上会有一些露珠，而这些露珠就像是它们的眼泪。小草也有感情，当它快乐的时候，它会挺直腰，享受阳光的温暖，微风的沐浴;当它哭泣的时候，它会弯下自己的腰;当它埋怨自己是颗不起眼的小草时，它已死去。让我们管好自己的脚，别再践踏草坪。用行动安抚已死去的灵魂，再度点燃生命的奇迹。

你看见过吗?几十个人的手里拿着电锯斧头，他们是要去砍伐树木。当森林出现电锯声时，将伴随着一棵棵树的倒下。当出现龙卷风和沙尘暴时，再也没有树木来挡风遮雨。到时再也没有后悔药可吃。没有了树，空气也变得不再清新。当你冷的时候，你去捡树木生火，可你的温暖却是牺牲一棵树换来的。有些树木生长了几百年甚至几千年，可就一把不起眼的斧头结束了它漫长的生命。多么坚强的树，不知当它倒下的那一瞬间，它想到了什么?多么顽强的树，可最终还是逃不过厄运的毒手。

朋友们，保护我们的环境，就是保护我们的地球。珍惜我们唯一的地球，就是珍惜我们的生命。当天空出现彩虹时，就说明垃圾回家了，小草笑了，大叔爷爷乐了，我们的地球妈妈没有在哭泣了。

环境保护(Protect environment)

The earth scale change of climate has brought a new kind of natural disaster and the developed and complicated city system is holding a latent risk of expanding the damage artificially. Also people has been spoiling the health since the immense quantity of chemicals have been produced and already used in pursuit of convenience and various toxic substances have been produced unintentionally and accumulated in environment. Therefore, We need some countermeasures from the viewpoint to prevent the city environment form disaster and to manage environmental risks. So we will develop and improve a new risk management system and a disaster prevention system to preserve and create the city environment where people feel easy and sound in their life.

[环境保护Protect environment的英语作文