万里长城是世界古代建筑的奇迹。早在春秋时期,楚国就修筑了长数百千米的非封闭性城墙,叫作方城。战国时,燕、赵、魏、韩、秦等都在边界筑起了长城。秦始皇统一天下后,把燕、赵、秦原有的北方长城连接起来,筑成西起临洮东至辽东的长城,长万余里。今山西大同北部,甘肃岷县城西等地均有秦长城遗址。
西汉沿河西走廊一带向西增筑朔方长城和河西长城,经玉门关延伸到今新疆境内,以保护河西走廊。北魏时西部柔然人满为患,又兴筑长城以防柔然人南侵。北齐也多次修筑长城。隋代为防御突厥、吐谷浑,数度修筑长城。明朝建立后,大将徐达曾18次在居庸关修筑长城。明长城西起甘肃嘉峪关,东至鸭绿江,这就是今天我们见到的万里长城。
明长城主体是城墙。山西东面至山海关一段,断面下宽上狭,平均底宽6米,高逾6.5米,外砌整齐条石和特大城砖,内部夯土。城墙顶部用三、四层砖铺砌,最上一层是方砖,用石灰勾缝,十分平正坚实,连野草也难以生根,平均宽5米,可容5马
并骑10人并进。墙顶两侧还砌有砖墙,内侧砌成约高1.5米的矮墙,外侧砌成约高1.5米的垛墙,每一垛牙上面有了望孔,下面有一射击眼。城墙上有排水沟、吐水嘴等设施,在关口和险要的地方还设有凸出的罗城。
修筑长城的工程浩大,筑长城所用土方如所来筑一道厚1米、高5米的墙,可绕地球一周有余。筑长城一般就地取材,大型城砖和石灰是就地烧制的。在高山峻岭,则开采石料,用石砌筑。在沙漠中,用红柳枝条和芦苇与砂石层层相间铺砌,可砌到6.5米以上。在黄土地区,大都取土垒筑,在重要地段的城墙一般用砖砌和条石镶砌
八月底是秋季了是去九寨沟的好时节,我是今年暑假的这个时候去的,是从成都亲戚家出发的。
网上搜索了一些线路,不过到了就在那边还是一下子就蒙了,茫茫景区,从这个景点到那个景点的,怎样走最省时间,我们全无概念,幸好送我们去景区的出租车师傅对景区很了解,一路上给我介绍哪些景点的特色,怎么走,简直比导游还厉害,导游费又省了,这位师傅还很幽默风趣,给我们介绍了很多当地文化,让我们一下子对当地觉得亲切多了,后来去黄龙,我们也是坐的这位师傅的车,一路上帮了我们不少忙,为了感激这位师傅,也方便后来亲戚们出行,途中经过雪宝顶,听潘师傅说黄龙与九寨的水都是由雪宝顶的冰雪而来的,而且雪宝顶的水晶也是很有名的,但为了自然保护所以每年限量开采,这也是雪宝顶的水晶不被众人所知的原因,我想人们也不愿从此看不到黄龙与九寨沟的风景吧!
一路上我感受到藏、羌族的文化。路上有个藏族姑娘搭车,为了感谢我们她给我们唱了首歌,歌声让我震惊,那是雪域高原的歌声,优美动听,让我对藏文化产生了浓厚的兴趣。
Dear Sir/Madam:
As a teacher at xxxx school, I am writing to provide you a recommendation for Miss/Mr.xx so as to help you assess her/his application for acceptance into your program and consideration for financial aid.
Considered a promising student with originality and sophistication in her/his thinking, (she/he was asked, in the spring semester of 2008, to develop a subsystem of a DBMS project for her B.S.thesis, for which I was the chief leader. T
his subsystem was designed to manage the information of materials in NO.1 Foundry Plant of Dongfeng Auto Works.To do the job, she/he read many books about software engineering and took some courses in Database Principles and Management. Keenly aware that the design of a DBMS decides the quality of the whole software system, she did her/his utmost from the beginning of the project.(参加过什么活动. From analyzing users requirements to designing the whole system, from the detailed designing to the final programming, she was very level-headed and full of innovation every step of the way. Taking full advantage of her ability and creativity, she firmly focused herself on her objective and gnored all distractions. She successfully reached her goal. In the final software testing, only a few bugs were found in her subsystem. My appreciation of her talelent was thus confirmed.Miss is a very personable woman, friendly and helpful, and she has always been a team player in her work.
I would greatly appreciate it if you could give her application for candidacy to your Ph.D. program favorable consideration. Should you need any further information in your deliberation, please do not hesitate to contact me.
Sincerely xxxx
日月潭湖中风光旖旎,景色如画。湖畔的山麓上还建有许多亭台楼阁,是观赏湖光山色的极好场所。四周秀美的自然景致中点缀着寺庙古塔,更显得感想幽雅。其中最引人的是潭南青龙山麓的玄奘寺和潭北山腰的文武庙。山麓建有玄奘寺,供奉唐代高僧玄奘法师,寺中悬有“民族法师”匾额一方。
寺前有一座白色柱子的门楼,画栋雕梁的楼顶,飞檐挑角,富有民族特色。寺中三楼有一小塔,供奉着玄奘法师的头顶灵骨。寺后的青龙山巅,几年前建了一座九层高塔,名曰“慈恩塔”。塔仿辽宋古塔式样,为八角宝塔,每层檐尾垂挂小钟,迎风叮当作响,登塔远眺,明潭风光,尽收眼底。有人说,在天高云淡时,于塔顶可望见西子湖畔六和塔的塔尖,虽近似神话,却反映了人们对祖国大陆的向往之情。
Dear Admission Committee:
Miss Pan Bei requested a letter of recommendation from me to support her application for graduate program at your university. As her teacher, I am pleased to comply with her request.
I first got to know Miss Pan when she enrolled at university and I was the assistant director of her class at that time. Being a professor for several years, I noticed that due to the lack of self-learning ability, it is really challenging for students, even those performing excellent in senior school, to keep up with the college speed. However, as a diligent girl without any solid background in Computer Science before college, she adapted quickly to the especially competitive environment in our department. At the end of the first year, she earned the 5th rank in her class, while ranking 1st among the girls. I was fairly impressed by her self-learning technique and exceptional efforts. Hence, I believe, goal-oriented, not afraid of inchoateness and with persistence, she has the quality to make achievements.
What distinguished her among her classmates, I think, was that she went far beyond acquiring excellent scores in the exams and instead got her range of knowledge enlarged. In spring, 2006, Miss Pan took the course I taught named Algebraic Structures and Combinatorial Mathematics. This inquisitive and assiduous young woman was sometimes the last to leave after my class, raising novel questions related to the subject. I found that she understood the knowledge in depth and detail. Furthermore, I still remember during the spring vocation in May, due to the break-down of my mail box, I missed her mails to discussing some questions. But the following week during the course time, she asked me directly. Her zeal for knowledge and the spirit to explore answers really leave me a deep impression. Finally, she was among the few students who got almost full marks in every test in class which showed her exceeding grasp of every chapter. Thus, I gave her 98/100 for the excellent performance in my course.
In summary, I have every reason to believe that Miss. Pan will make outstanding performance at your university as a graduate. I would appreciate greatly if you give her a favorable consideration. Please feel free to contact me directly if more assistance is needed. Faithfully yours,
Wanling Qu, Professor
Department of Computer Science and technology Peking University
Email: qwku.edu.cn
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