1.求一篇2分钟的英语命题演讲

We have only one earthToday the earth is destroyed so terribly from the air to the land. In most of cities in all over the world, people always have to live in the polluted air. Heavy traffic and factories cause this. The gas, which is made by the cars and factories, is poisonous. They cause air pollution in the city. As a result, in 1952, thick dark pieces of cloud came down over London. People called it " a pea-soupier ". The smog was rather dangerous, especially to the old people and the young children. Thousands of them died. So in 1956 the British government decided to amend the law to keep the air clean. It stopped people from burning dirty coal in house and factories in the city. We can not live without air. So we must do everything possible to keep it clear and clean.The area of desert is growing every year. This is a serious problem all over the world. about 350 years ago, nearly half of the USA was covered with forest. But now there is no one third left. The forest has almost gone and a lot of good land has gone with it. The reason for this is that too many trees are cut down. So when it rains, the soil is washed away, leaving only sand, but no trees and no any good land. No land means we will have no food. Then how can we go on living in the future? So we must try our best to plant more and more trees in order to protect the land.We have only one earth .If we do not take good care of it, we will have no places to live on.。

2.电子邮箱投稿地址 要最新的

《时代青年》杂志编辑郜艳 cngaoyan@263.net

《风流一代》杂志编辑郑儒凤zhengzheng911@163.net

《深圳青年.国际》杂志编辑慧慧： hhwwjb@163.net jessica@zhaoni.com

《女友》杂志编辑莎梨pierluo@eyou.com

《爱人》杂志编辑贾琼 xajiaqiong@263.net

《楚风.新故事》杂志编辑罗尔luoer@963.net

《青春阅读》杂志社 qcyd@eyou.com

《花溪》杂志编辑木每yxmumei@yeah.net

《年轻人》杂志编辑王琳lz_youth@21cn.com

《课堂内外.高中版》杂志社youth.com@163.net

《辽宁青年》杂志编辑一风 shinwafly@163.com

《青年心理》杂志编辑李明宇limingyu5858@sina.com

《求职与打工》杂志编辑王学亮wxl001@371.net

《中国大学生》杂志编辑李东辉sunboy2277@sina.com

《女报.记实》杂志编辑肖海生xiaohscn@yahoo.com.cn

《女报.时尚》杂志编辑小王dancthwolf@163.net

《花季.雨季》杂志编辑顿号xudunhao@263.net

《新空间》杂志社zhonglj@21cn.com xkjzk@sohu.com

《中国青年》杂志社编辑徐风 a85602541@eyou.com

《广西文学.情感真品》杂志编辑韦露 alu99@163.net

《莫愁》杂志陆编辑 lay@mochou.com

《时代姐妹》杂志编辑蒹葭 hongdou9526@sina.com

《爱情故事》 why759@sina.com

《女士》李晓洁编辑 aihc@163.com

《大学时代》荷洁编辑 hejie604@sohu.com hejie604@sina.com

《新青年》陈大霞编 cdx@0451.com

《青少年文汇》骆洪亮编辑 YAZI-9426@163.COM

《知音.打工》郭敏编辑 gm@zhiyin.com.cn

《新女性》子规 cqxiaojing@163.com shekecidian@sina.com

《中国校园文学》谷美珏编辑 cake1980@sina.com

《华夏少年》张超编辑 杂志信箱：hxsn_home@163.com

依怡信箱：zcyilan@sina.com

3.本人急需一篇关于土木概论的论文

土木工程的英文是Civil Engineering ，直译是民用工程，它是建造各种工程的统称。

它既指建设的对象，即建造在地上，地下，水中的工程设施，也指应用的材料设备和进行的勘测，设计施工，保养，维修等专业技术。 土木工程随着人类社会的进步而发展，至今已经演变成为大型综合性的学科，它已经出许多分支，如：建筑工程，铁路工程，道路工程，桥梁工程，特种工程结构，给水排水工程，港口工程，水利工程，环境工程等学科。

土木工程共有六个专业：建筑学，城市规划，土木工程，建筑环境与设备工程，给水排水工程和道路桥梁工程。 土木工程作为一个重要的基础学科，有其重要的属性：综合性，社会性，实践性，统一性。

土木工程为国民经济的发展和人民生活的改善提供了重要的物质技术基础，对众多产业的振兴发挥了促进作用，工程建设是形成固定资产的基本生产过程，因此，建筑业和房地产成为许多国家和地区的经济支柱之一。 古代的土木工程有很长的时间跨度，大致从公元前500年新石器时代出现原始的土木工程活动到16世纪末意大利的文艺复兴，导致土木工程走上迅速发展的道路为止，前后经历了两千多年。

在这段时间内，由于科学理论发展及其缓慢，土木工程也没有突破习惯的发展。 远古时代，居住和交往的需要，人类开始了掘土为穴，架木为桥的原始的土木工程活动，我国黄河流域的仰邵文化遗址和西安半坡遗址发现了有供居住的浅穴和直径为5—6米的圆形房屋。

中国古代的建筑多采用木结构，并逐渐形成与此想适应的风格，公元14世纪的建造的北京故宫是世界上最大的最完整的古代木结构宫殿建筑群，应县的木塔是世界上最高的木建筑。与此同时，欧洲的以石拱结构为主的古代房屋建筑也达到了很高的水平，意大利的比萨大教堂，法国的巴黎圣母院，罗马的圣彼得大教堂均反映了欧洲这一时期建筑施工和结构的最高成就。

从17世纪中页开始到20 世纪40年代第二次世界大战结束为止的300年间，国外的建筑取得了长足的进步。土木工程进入了定量分析阶段。

一些理论的发展，新材料的出现，新工具的发明，都使土木工程科学日渐完善和成熟。到了近代，二战结束之后，许多国家经济起飞，现代科学日益进步，从而为进一步发展提供了强大的动力和物质基础。

尤其是我国，土木工程在这一段时间内，更是突飞猛进，建筑，桥梁，道路，隧道等，无论是在技术理论上，还是在基础建设上，都取得了巨大的成就。 人们生活水平的不断提高，必然要求越来越舒适的居住环境，在这种情况下，建筑的发展直接推动了土木工程的发展。

远古时代，人们巢居穴处，后来石器的出现，人们开始利用工具建造简单的住房，到明清时期，中国的木结构建筑技术和规模都达到了顶峰。解放，随着国家对基础建设的投入的不断加大，一座座高楼想雨后春笋一样出现在中华大地。

建筑工程就是兴建房屋规划，勘测，设计，施工的总称。目的是为人类的生产和生活提供场所。

房屋建筑一般包括十个部分：（1）埋在地下的基础和地下室（2）承载外力并把力传到基础的柱子，楼板，梁，框架墙，屋盖及支撑体系（3）四周的饿维护结构和中间的隔墙（4）房屋内外的装饰（5）控制环境的供暖，通风，空气调节，照明，防火隔声等系统（6）楼梯间，电梯或自动扶梯等垂直传输系统（7）闭路电视，电话，计算机网络等通讯体系（8）电力系统（9）卫生设备和给水排水系统（10）垃圾处理系统。 Pier Luigi Nervy说过：建筑结构说穿了，不过就是受力体的反力与内部应力如何与外力达到平衡。

建筑首先要解决，也是必须要解决的问题就是受力的问题。我们把解决这个问题的学科称为建筑力学。

建筑力学有可以分为：静力学，材料力学和结构力学三大力学体系。建筑力学是讨论和研究建筑结构及构件在荷载和其他因素影响的工作状况，也就是建筑的强度，刚度，稳定性。

在载荷作用下，承受载荷和传递载荷的建筑结构和构件会引起周围的物体对它们的作用，同时物件本身受载荷作用而产生变形，并且存在着破坏的可能性，但是结构本身就具有一定的抵抗变形和破坏的能力，而结构的承载能力的大小是与构件的材料，截面的几何尺寸，受力性质，工作条件和构造情况有关。而这些关系都可以由力学关系式通过计算而得以解决。

建筑材料在建筑中也有着举足轻重的作用。建筑材料是随着人类社会生产力和科学技术的提高而逐步发展起来的。

人类最早穴居巢处，几乎没有建筑材料的概念，后进入到石器铁器时代，开始掘土凿石为洞，伐木搭竹为棚，利用最原始的材料建造最简陋的房屋。后来，用黏土烧制砖瓦，用岩石制石灰，石膏，建筑材料从天然进入了人工阶段，为建造教大的房屋创造了条件。

18世纪后，科学技术的发展促使建筑材料进入了一个新的发展阶段，钢铁，水泥，混凝土及其他材料的相继问世，为现代的建筑奠定了基础。20世纪后，建材性能和质量的弊端改善，品种的不断增加，以有机材料为主的化学建材异军突起，一些具有特殊功能的建材如绝热材料，吸声隔热材料，耐火防火材料，防水抗渗材料，防爆防辐射材料应运而生，这些材料为房屋建筑提供。

4.跪求有关 楼兰的消失 英文演讲稿 语法要正确,通常,最好再带上中文

Loulan's disappearance:Recently, LuoBuBo environment of scientific expedition team LuoBuBo drilling for the comprehensive system of environmental science. According to preliminary infer that sometime in the qinghai-tibet plateau, with seven to eight million years ago, the rapid uplift LuoBuBo bysouthing north migration, drying, resulting in increased gradually whole lakes dry. Such an explanation is not satisfactory, Chinese academy of sciences institute of geology and geophysics ZhouKun professor argues that, uncle LuoBuBo dry complex reasons. It is a global problem, and regional issues, besides natural causes, and human factors.A global climate is dry, the big background Human and neolithic in here, the Bronze Age here, then just value population prosperous period, the temperature LuoBuBo, environment. But then, after entering cooling zone, river water environment, lakes, desert expansion. At about 2000 BC, the performance of drought in north China area in loess accumulation, ice, lakes, retreat.The disappearance of the ancient lou-lan and about in the fourth century to the han dynasty to the north (central), then it intensifies the dry periods. In fact, the dry process, not only is the ancient lou-lan and desert expansion, and successively occur in kelatongke pier, hananiah, milan, soil, and integration of khan city of wancheng etc.Second, the qinghai-tibet plateau uplift is geography Besides global climate change, the uplift of qinghai-tibet plateau is the most important cause of regional. In seven to eight million years ago, the rapid uplift of qinghai-tibet plateau. The uplift of northwest China's climate decisive role. LuoBuBo due to the geographical location is located in east Asia and the Pacific northwest inland, every year and the Indian Ocean warm air almost all rarely reach here.When the global climate change, the east west began to appear the drought and desertification, gobi tendency. During this period, LuoBuBo started from the south to the north. 7 million years ago, when the lake near lake to the last drop dramatically. Because of the uneven terrain lake, the ancient great unity of LuoBuBo decomposing now, and manasseh kelatongke lake, north of lake and LuoBuBo larger.In regional factors, there must be worthy of note, from the remote sensing data said recently, which had a big upstream of the landslide. The landslide whole blocked river channels, which was broken LuoBuBo of water. The question now is still don't know the exact time the landslide occurred in, whether it LuoBuBo dry before remains to study.Third, LuoBuBo accelerate human development Human activities on the LuoBuBo dry effect, more recent in late may. Waste water and trees are the key oasis can survive. Loulan city was established in kongquehe downstream of the water resources, there was a growing HuYangShu exuberant the materials for the building. When people in LuoBuBo edge loulan diameters for 10 million square meters of loulan city, they cut off many trees and reed, it will undoubtedly on environment.In this period, human activities and the changes of water damage, make the war and the fragile worsening ecological environment. 5 the "river churchyard density, root stump" male who had felt loulan survival crisis, to pray tribe to bless his sons reproduction worship. But they cut the trees, already scarce has deteriorated to the local environment.The final LuoBuBo dry, and in the tarim river upstream of the liberation of our development. When we in tarim river upstream of the tarim river after water diversion, bills, appear to flow downstream. This point in recent years from the Yellow River dry-up can get by. No water supplies because of LuoBuBo also began shrinking, eventually finally die.（中文对照）楼兰的消失： 最近，中科院罗布泊环境钻探科学考察队对罗布泊进行了全面系统的环境科学考察。

考察队认为：据初步推断，随着青藏高原在距今7到8万年前的快速隆升，罗布泊由南向北迁移，干旱化逐步加剧，最后导致整个湖泊干涸。这样的一个解释显然并不能让人满意，中国科学院地质与地球物理研究所的周昆叔教授则认为，罗布泊干涸的原因很复杂。

这里面既是全球性的问题，也是地域性的问题，除了自然方面的原因，还有人为方面的因素。 一、全球气候旱化是大背景 新石器时代人类便涉足这里，青铜器时代这里人口繁盛，这时恰值高温期，罗布泊湖面广阔，环境适宜。

但此后进入降温区后，水土环境变差，河水减少，湖泊缩减，沙漠扩大。在距今约2000年左右旱化加剧，这表现在中国北方广大地区冰进发生，黄土堆积，湖沼消亡，海退发生。

楼兰古城的消亡大约在公元前后至四世纪（中原的汉朝到北魏时期），这时正是旱化加剧的时期。其实，在这。

5.有谁知道这篇英语短文

欧亨利的《麦琪的礼物》 THE GIFT OF THE MAGI by O. Henry One dollar and eighty-seven cents. That was all. And sixty cents of it was in pennies. Pennies saved one and two at a time by bulldozing the grocer and the vegetable man and the butcher until one's cheeks burned with the silent imputation of parsimony that such close dealing implied. Three times Della counted it. One dollar and eighty- seven cents. And the next day would be Christmas. There was clearly nothing to do but flop down on the shabby little couch and howl. So Della did it. Which instigates the moral reflection that life is made up of sobs, sniffles, and smiles, with sniffles predominating. While the mistress of the home is gradually subsiding from the first stage to the second, take a look at the home. A furnished flat at $8 per week. It did not exactly beggar description, but it certainly had that word on the lookout for the mendicancy squad. In the vestibule below was a letter-box into which no letter would go, and an electric button from which no mortal finger could coax a ring. Also appertaining thereunto was a card bearing the name "Mr. James Dillingham Young." The "Dillingham" had been flung to the breeze during a former period of prosperity when its possessor was being paid $30 per week. Now, when the income was shrunk to $20, though, they were thinking seriously of contracting to a modest and unassuming D. But whenever Mr. James Dillingham Young came home and reached his flat above he was called "Jim" and greatly hugged by Mrs. James Dillingham Young, already introduced to you as Della. Which is all very good. Della finished her cry and attended to her cheeks with the powder rag. She stood by the window and looked out dully at a gray cat walking a gray fence in a gray backyard. Tomorrow would be Christmas Day, and she had only $1.87 with which to buy Jim a present. She had been saving every penny she could for months, with this result. Twenty dollars a week doesn't go far. Expenses had been greater than she had calculated. They always are. only $1.87 to buy a present for Jim. Her Jim. Many a happy hour she had spent planning for something nice for him. Something fine and rare and sterling--something just a little bit near to being worthy of the honor of being owned by Jim. There was a pier-glass between the windows of the room. Perhaps you have seen a pier-glass in an $8 flat. A very thin and very agile person may, by observing his reflection in a rapid sequence of longitudinal strips, obtain a fairly accurate conception of his looks. Della, being slender, had mastered the art. Suddenly she whirled from the window and stood before the glass. her eyes were shining brilliantly, but her face had lost its color within twenty seconds. Rapidly she pulled down her hair and let it fall to its full length. Now, there were two possessions of the James Dillingham Youngs in which they both took a mighty pride. One was Jim's gold watch that had been his father's and his grandfather's. The other was Della's hair. Had the queen of Sheba lived in the flat across the airshaft, Della would have let her hair hang out the window some day to dry just to depreciate Her Majesty's jewels and gifts. Had King Solomon been the janitor, with all his treasures piled up in the basement, Jim would have pulled out his watch every time he passed, just to see him pluck at his beard from envy. So now Della's beautiful hair fell about her rippling and shining like a cascade of brown waters. It reached below her knee and made itself almost a garment for her. And then she did it up again nervously and quickly. once she faltered for a minute and stood still while a tear or two splashed on the worn red carpet. On went her old brown jacket; on went her old brown hat. With a whirl of skirts and with the brilliant sparkle still in her eyes, she fluttered out the door and down the stairs to the street. Where she stopped the sign read: "Mne. Sofronie. Hair Goods of All Kinds." One flight up Della ran, and collected herself, panting. Madame, large, too white, chilly, hardly looked the "Sofronie." "Will you buy my hair?" asked Della. "I buy hair," said Madame. "Take yer hat off and let's have a sight at the looks of it." Down rippled the brown cascade. "Twenty dollars," said Madame, lifting the mass with a practised hand. "Give it to me quick," said Della. Oh, and the next two hours tripped by on rosy wings. Forget the hashed metaphor. She was ransacking the stores for Jim's present. She found it at last. It surely had been made for Jim and no one else. There was no other like it in any of the stores, and she had turned all of them ins。