出國留學(xué)的介紹信

出國留學(xué)的介紹信(集錦15篇)

　　隨著社會一步步向前發(fā)展，我們需要用到介紹信的情形越來越多，介紹信是機(jī)關(guān)、團(tuán)體、企事業(yè)單位介紹本單位的人員到其他單位接洽、聯(lián)系、磋商工作和事情等所寫的一種專用書信。那么你有了解過介紹信嗎？下面是小編整理的出國留學(xué)的介紹信，歡迎大家分享。

出國留學(xué)的介紹信1

　　Dear Colleagues：

　　As a teacher in Department of Biology, Nankai University, a leading university in China, I am very pleased to take this opportunity to recommend one of my favorite students to your PhD program.

　　In September, 20xx, Miss Zhang was my students in General Biology, the first professional course they take in the field. She likes it very much. I teach her in an open and interactive manner, she is active and passionate about answering class questions. Miss Zhang is bright, energetic and enthusiastic girl who loves speaking out her own ideas. She never escapes from those points of which she is skeptical. Apart from that, she often puts forward her ideas upon questions and exchanges all of her innovate ideas with me after class.

　　Upon ending of General Biology course, I asked my students to write an essay upon their understanding of biology. I discovered Miss Zhang’s essay was so impressive and persuasive; her careful essay comes from dozens of references to Biology literatures. In essay Miss Zhang stretched out her creative thinking upon status quo of biological research and branches in the field of biology. All of this speaks to her creative and logical and scientific thinking capability. I am gladly to say that Miss Zhang has a clear understanding about General Biology, that comprehension has been reflected fully in her essay. Therefore Miss Zhang got a full point for her essay in her class, and other students took it as model essay for granted.

　　I believe Miss Zhang’s industriousness, passion and dedication will make her an ideal candidate you are seeking for your program, so I highly recommend her without any hesitation to you. And I will greatly appreciate it if you could accept her into your program.

　　Sincerely yours,

出國留學(xué)的介紹信2

　　At the request of Mr.Xizhen Chen,my former student in the Department of Computer Science,Beijing Univ.of Sciences,I am glad to write this letter furnishing my uation ofhis academic aptitude for your reference.Mr.Chen is interested in your graduate program in Computer Science.I came to know him in September 1987 when Mr.Chen enrolled in my class on FORTRAN IV Programming,a three semesterscourse.In the class he was one of the most outstanding students.At the semester final he earned ahigh grade of 81,which should beAaccording to our grading system.I also ound him good at other studies.After the class,he had personal talks with me several times.

出國留學(xué)的介紹信3

　　Dear Colleagues：

　　As a teacher in Department of Biology, Nankai University, a leading university in China, I am very pleased to take this opportunity to recommend one of my favorite students to your PhD program.

　　In September, 20xx, Miss Zhang was my students in General Biology, the first professional course they take in the field. She likes it very much. I teach her in an open and interactive manner, she is active and passionate about answering class questions. Miss Zhang is bright, energetic and enthusiastic girl who loves speaking out her own ideas. She never escapes from those points of which she is skeptical. Apart from that, she often puts forward her ideas upon questions and exchanges all of her innovate ideas with me after class.

　　Upon ending of General Biology course, I asked my students to write an essay upon their understanding of biology. I discovered Miss Zhangs essay was so impressive and persuasive; her careful essay comes from dozens of references to Biology literatures. In essay Miss Zhang stretched out her creative thinking upon status quo of biological research and branches in the field of biology. All of this speaks to her creative and logical and scientific thinking capability. I am gladly to say that Miss Zhang has a clear understanding about General Biology, that comprehension has been reflected fully in her essay. Therefore Miss Zhang got a full point for her essay in her class, and other students took it as model essay for granted.

　　I believe Miss Zhangs industriousness, passion and dedication will make her an ideal candidate you are seeking for your program, so I highly recommend her without any hesitation to you. And I will greatly appreciate it if you could accept her into your program.

　　Sincerely yours,

出國留學(xué)的介紹信4

　　Research Fellow and Professor

　　The Institute of European and American Studies

　　Academia Sinica

　　ear Admissions com#mittee:

　　Among all the students who have received my instruction in the courses of “International Marketing” and “Strategic Management” at ABC University, Mr. John Doe is one of the few who stood out and left with me a positive impression. Therefore, I am confident to recom#mend this young man to your prestigious MBA program.

　　John is a bright and aggressive individual who possesses a strong motivation to learn and excel in his course work. Unlike most of his peers, who gained knowledge merely from school lecturing, John would spend a great amount of efforts and time in reading outside articles and textbooks and share his ideas with the class. In addition, as an open- minded individual who never let go any learning experience, John often came to me discussing various questions and problems he encountered in his coursework.

　　I would like hereby to draw upon an instance that I believe fully exemplifies John’s academic ability. While attending my class he presented an excellent report focusing on the research of the European com#munity (EC), in which he shared with us his careful observations on EC, and proposed a number of innovative suggestions for Chinese Taiwanese industries that wished to gain successful presence in that market. Having noticed his superior ability to conduct independent research studies and to support his arguments with logical quantitative analyses, I recom#mended John to submit his paper to the Accounting & Statistics Quarterly published by the Executive Yuan of R.O.C.. Needless to say, John has acquired very high marks in both of my courses.

　　The very positive impression made by John has been repeatedly re- enforced by his strong performance in various extracurricular activities. John has managed to earn full confidence from me in his sound managerial potential by demonstrating an intelligence, aggressiveness, and leadership quality in both academic and extracurricular contexts.

　　In general, I consider John a very promising applicant to your esteemed MBA program. I have the least reservation on his potential to succeed in his future educational as well as professional pursuit, and will be more than happy to discuss with you any matters pertaining to this reference letter.

　　Sincerely yours,

　　Jerry Smith, Ph.D. Professor

出國留學(xué)的介紹信5

　　At the request of Mr.Xizhen Chen,my former student in the Department of Computer Science,Beijing Univ.of Sciences,I am glad to write this letter furnishing my uation ofhis academic aptitude for your reference.Mr.Chen is interested in your graduate program in Computer Science.I came to know him in September 1987 when Mr.Chen enrolled in my class on FORTRAN IV Programming,a three semesters’’course.In the class he was one of the most outstanding students.At the semester final he earned ahigh grade of 81,which should be"A"according to our grading system.I also ound him good at other studies.After the class,he had personal talks with me several times.

　　He indicated agreat interest in computer hardware,In my opinion,Mr.Chen has apotential in Computer Science,which can be further developed.In view of his previous achievements in this College,I am firmly convinced that Mr.Chen will make asuccessful graduate student.Your favorable consideration of his admission will be hi ghly appreciated.

出國留學(xué)的介紹信6

　　To whom it may Concern,

　　I am writing this letter to attest to Pauls skills in language and public relations. In the four years I have known him, I have been consistently impressed with his ability not only to negotiate complex ideas in other languages, but also to relate these things in a personable, conscientious fashion. His manner in these cases is both professional and personal, two qualities which I find particularly valuable in a professional setting. He has personally helped me in professional negotiation for everything from train tickets to contract information, and I have always been able to count on him.

　　I first met Paul in school, where he was a student at the university at which I taught. He was well-known to most of the westerners in town, who could call from different universities to ask for his help. Sometimes this help involved translation of professional documents, and sometimes it involved personal help in making phone calls. Many of these westerners continue to call him today, even though they live quite far away from him, because they have come to trust him very much. From this foundation in public relations Paul has found positions in various professional capacities and has been highly-valued in each place. He is generally the sort of employee a company finds most valuable in its dealings with both foreign and domestic clients. He puts people at their ease with his language ability and manner, both of which communicate to people that they can relax and simply communicate.I would highly recommend Paul as an employee. His experience and manner are rare and very valuable.

　　Robert Moore

　　Mentor

出國留學(xué)的介紹信7

　　To Whom It May Concern:

　　As the Dean of Stonewell College, I have had the pleasure of knowing Hannah Smith for the last four years. She has been a tremendous student and an asset to our school. I would like to take this opportunity to recommend Hannah for your graduate program. I feel confident that she will continue to succeed in her studies. Hannah is a dedicated student and thus far her grades have been exemplary. In class, she has proven to be a take-charge person who is able to successfully develop plans and implement them. Hannah has also assisted us in our admissions office. She has successfully demonstrated leadership ability by counseling new and prospective students.

　　Her advice has been a great help to these students, many of whom have taken time to share their comments with me regarding her pleasant and encouraging attitude. It is for these reasons that I offer high recommendations for Hannah without reservation. Her drive and abilities will truly be an asset to your establishment. If you have any questions regarding this recommendation, please do not hesitate to contact me. Sincerely, Roger Fleming Dean of Stonewell College 。

出國留學(xué)的介紹信8

　　At the request of Mr. Xizhen Chen, my former student in the Department of Computer Science, Beijing Univ. of Sciences, I am glad to write this letter furnishing my evaluation ofhis academic aptitude for your reference. Mr. Chen is interested in your graduate program in Computer Science.I came to know him in September 1987 when Mr. Chen enrolled in my class on FORTRAN IV Programming, a three semesters’ course.In the class he was one of the most outstanding students. At the semester final he earned a high grade of 81, which should be "A" according to our grading system. I also ound him good at other studies.After the class, he had personal talks with me several times. He indicated a great interest in computer hardware,

　　In my opinion, Mr. Chen has a potential in Computer Science, which can be further developed.In view of his previous achievements in this College, I am firmly convinced that Mr. Chen will make a successful graduate student. Your favorable consideration of his admission will be highly appreciated.

出國留學(xué)的介紹信9

尊敬的xx：

　　申請人xx，男，25歲，19xx年08月05日出生，20xx年7月畢業(yè)于xxxx旅游管理專業(yè)。

　　我喜歡旅游，大學(xué)我選擇了旅游管理專業(yè)，開始系統(tǒng)學(xué)習(xí)旅游管理知識，課程涉及xx國家的旅游文化，當(dāng)時xx國家獨(dú)特的文化內(nèi)涵給了我很大的感觸，我想自己畢業(yè)后如果能到xx國家進(jìn)一步學(xué)習(xí)，對開闊視野提升知識面一定會有很大的幫助，但是要去xx國家，語言是首先要解決的'問題，畢業(yè)后，我選擇到煙臺昂立外語學(xué)院學(xué)xx國家語，經(jīng)過一段時間的學(xué)習(xí)，我發(fā)現(xiàn)國內(nèi)學(xué)校教的大都為書面化的東西，只有到xx國家才能領(lǐng)悟到精確的本土文化，我跟父母說了我的想法，父母表示大力支持，，并且他們已經(jīng)為我提供了足夠的留學(xué)資金。

　　正好有朋友給我推薦了白石大學(xué)，這所大學(xué)可以先學(xué)習(xí)基礎(chǔ)語言后學(xué)習(xí)專業(yè)，我覺得挺不錯，為了我的夢想，我會在學(xué)校努力學(xué)習(xí)語言，語言合格后，繼續(xù)留在本校讀研，相信本校的專業(yè)一定會讓我學(xué)有所成的。

　　學(xué)成回國后，我準(zhǔn)備開個主題旅游策劃公司，實(shí)踐自己所學(xué)知識。我對所學(xué)的這個專業(yè)充滿激情和動力，當(dāng)然，我更熱愛我的祖國和爸爸媽媽，相信通過我的努力，我會更好的回報祖國的培養(yǎng)和爸媽的養(yǎng)育之恩。

此致

敬禮！

介紹人：

　　20xx年xx月xx日

出國留學(xué)的介紹信10

　　Dear Sir:

　　It is my pleasure to recom#mend Mr. Fu-ping Wang for his application to graduate studies in your school.

　　Mr. Wang has been my research assistant of the National Science Councils project The United States and the United Nations Financial Crisis: The Role of U.S. Congress since September 1997. His major responsibilities include information collecting, analyzing and translating. He is an enthusiastic and progressive young man with extremely high potentiality. Mr. Wang is not only quick at learning and good at solving difficult problems, but also with a logical mind that enables him to effectively analyze difficulties. All the work handed to him was com#pleted satisfactorily. Actually, he is so reliable that I assign him with heavy responsibilities. With his help, I have been able to spend more time in writing the research paper. I really consider myself very fortunate to have such a capable assistant.

　　I am certain his diligence, coupled with a good com#petence and pleasant personality, will assure him of academic achievements in his future academic pursuits. I strongly recom#mend his admission without any reservation.

　　Sincerely yours,

　　Chung Wei-kuo

出國留學(xué)的介紹信11

　　【出國留學(xué)注意事項(xiàng)】

　　一、家長應(yīng)當(dāng)建立出國留學(xué)的應(yīng)急通訊錄

　　出國留學(xué)留學(xué)學(xué)子中曾經(jīng)發(fā)生過家長了解到孩子處于危險之中，卻因?yàn)闆]有及時聯(lián)系當(dāng)?shù)鼐�方，從而未能阻止悲劇發(fā)生的情況。所以家長應(yīng)該了解孩子在海外就讀學(xué)校院系、國際學(xué)生處的聯(lián)系方式，以及當(dāng)?shù)貙W(xué)校的應(yīng)急電話。便于一旦有事可以第一時間和學(xué)校聯(lián)系。此外，還可以讓孩子提供好友、室友、就讀學(xué)校的中國學(xué)生學(xué)者聯(lián)誼會主要負(fù)責(zé)人的聯(lián)系方式，以便于家長在語言上沒有障礙的及時了解留學(xué)生情況。

　　二、出國后，時刻注意留學(xué)生們的心理和思想健康

　　近年來，出國留學(xué)很多事例表明留學(xué)學(xué)子的心理和思想健康已成為需要重點(diǎn)關(guān)注的安全事項(xiàng)。建議家長與子女能夠通過電話、Email、QQ、MSN、Googletalk、Skype等即時通訊方式保持定期的聯(lián)系和溝通，了解他們在海外的學(xué)習(xí)生活狀況、思想、心態(tài)和情緒上的變化，并積極的在各種問題上給予留學(xué)生們正確的指導(dǎo)。其中包括在國外學(xué)習(xí)方法的調(diào)整與適應(yīng)、樹立正確文明的人生價值觀和戀愛婚姻觀以及為人處事的方式等。

　　三、時常與出國留學(xué)留學(xué)生們保持聯(lián)系，關(guān)注他們的生活和出行安全

　　出國留學(xué)孩子出國后的安全問題一直是家長重點(diǎn)關(guān)注的問題之一�？傮w來講，國外，特別是美國、英國等發(fā)達(dá)國家大多數(shù)地區(qū)都是安全的。但是很悲痛的是每年都會聽聞到一些留學(xué)生的安全事件。絕大多數(shù)是出自留學(xué)生在駕車出游時或者在日常生活上的安全疏忽，而導(dǎo)致的不同程度的傷亡事故。在這些事故中，甚至有些家長在孩子出事數(shù)日后仍然不知道事故的發(fā)生。因此，安全問題也應(yīng)被家長和留學(xué)生們常掛心頭，不能松懈。建議家長應(yīng)定期與孩子保持聯(lián)系，并時常提醒他們注意各項(xiàng)日常生活和外出活動時的安全。

　　四、協(xié)助出國留學(xué)留學(xué)生們做好理財規(guī)劃和提高財產(chǎn)安全管理意識

　　出國留學(xué)現(xiàn)在有許多留學(xué)學(xué)子都不太會管理自己的財務(wù)，在沒人監(jiān)管的情況下，過度消費(fèi)的現(xiàn)象容易出現(xiàn)。因此，家長需要適當(dāng)?shù)膸椭�孩子做好理財�?guī)劃。另一方面是財產(chǎn)安全問題，有時一不小心就會被不法分子通過不同渠道和不同手段敲詐勒索或盜取錢財。家長應(yīng)及時了解孩子的資金狀況，并幫助孩子提高自我保護(hù)的意識，避免不必要的傷害和財產(chǎn)損失。

　　五、教導(dǎo)出國留學(xué)留學(xué)生提高法律意識，增強(qiáng)自我保護(hù)

　　出國留學(xué)外國的法律與中國多有不同，家長應(yīng)該教導(dǎo)孩子自覺地學(xué)習(xí)和遵守當(dāng)?shù)氐姆�律、法�?guī)與文化，同時學(xué)會運(yùn)用法律保護(hù)自身的合法權(quán)益。涉及留學(xué)生的法律通常有民法、刑法、交通法、鄰里法、婚姻法、消費(fèi)法、環(huán)境保護(hù)法、野生動物保護(hù)法、公共秩序法、打工法、移民法等。同時，每個學(xué)校也有各自的`相關(guān)管理規(guī)定，比如學(xué)籍、考勤、考試、圖書館借閱、資料復(fù)印、作業(yè)抄襲、交費(fèi)管理、住宿管理等。在需要時，應(yīng)向?qū)�業(yè)機(jī)構(gòu)或?qū)�業(yè)人士咨詢和尋求幫助。

　　【出國留學(xué)貸款申請條件】

　　一、出國留學(xué)貸款申請條件

　　貸款者的貸款用途都是用于留學(xué)者的學(xué)雜費(fèi)和生活費(fèi)

　　貸款者的年齡要在貸款到期日時不超過55周歲。

　　二、出國留學(xué)貸款申請資料

　　1.您的有效身份證明，出示本人的護(hù)照原件并提供其復(fù)印件存檔;

　　2.就讀學(xué)校的《錄取通知書》，所讀學(xué)校開出的學(xué)生學(xué)習(xí)期內(nèi)所需學(xué)雜費(fèi)總額的證明資料;如按學(xué)年度發(fā)放的貸款，您應(yīng)于每個學(xué)年結(jié)束前出示下一年度學(xué)雜費(fèi)證明。

　　3.以財產(chǎn)作抵押或質(zhì)押的，應(yīng)提供抵押物、質(zhì)物清單和有處分權(quán)人(包括財產(chǎn)共有人)簽署的同意抵押、質(zhì)押的承諾或聲明。對抵押物須提交由有關(guān)部門出具的價值評估報告和保險部門的保險文件，對質(zhì)押物須提供權(quán)利證明文件。

出國留學(xué)的介紹信12

　　at the request of mr.xizhen chen,my former student in the department of computer science,beijing univ.of sciences,i am glad to write this letter furnishing my uation ofhis academic aptitude for your reference.mr.chen is interested in your graduate program in computer science.i came to know him in september 1987 when mr.chen enrolled in my class on fortran iv programming,a three semesters’’course.in the class he was one of the most outstanding students.at the semester final he earned ahigh grade of 81,which should be"a"according to our grading system.i also ound him good at other studies.after the class,he had personal talks with me several times.

　　he indicated agreat interest in computer hardware,in my opinion,mr.chen has apotential in computer science,which can be further developed.in view of his

　　previous achievements in this college,i am firmly convinced that mr.chen will make asuccessful graduate student.your favorable consideration of his admission will be hi ghly appreciated.

出國留學(xué)的介紹信13

尊敬的領(lǐng)導(dǎo)：

　　XXX，男，XXX年7月畢業(yè)于XXXX旅游管理專業(yè)。

　　我喜歡旅游，大學(xué)我選擇了旅游管理專業(yè)，開始系統(tǒng)學(xué)習(xí)旅游管理知識，課程涉及XX國家的旅游文化，當(dāng)時XX國家獨(dú)特的文化內(nèi)涵給了我很大的感觸，我想自己畢業(yè)后如果能到XX國家進(jìn)一步學(xué)習(xí)，對開闊視野提升知識面一定會有很大的.幫助，但是要去XX國家，語言是首先要解決的問題，畢業(yè)后，我選擇到煙臺昂立外語學(xué)院學(xué)XXX國家語，經(jīng)過一段時間的學(xué)習(xí)，我發(fā)現(xiàn)國內(nèi)學(xué)校教的大都為書面化的東西，只有到XX國家才能領(lǐng)悟到精確的本土文化，我跟父母說了我的想法，父母表示大力支持，并且他們已經(jīng)為我提供了足夠的留學(xué)資金。正好有朋友給我推薦了xx大學(xué)，這所大學(xué)可以先學(xué)習(xí)基礎(chǔ)語言后學(xué)習(xí)專業(yè)，我覺得挺不錯，為了我的夢想，我會在學(xué)校努力學(xué)習(xí)語言，語言合格后，繼續(xù)留在本校讀研，相信本校的專業(yè)一定會讓我學(xué)有所成的。學(xué)成回國后，我準(zhǔn)備開個主題旅游策劃公司，實(shí)踐自己所學(xué)知識。我對所學(xué)的這個專業(yè)充滿激情和動力，當(dāng)然，我更熱愛我的祖國和爸爸媽媽，相信通過我的努力，我會更好的回報祖國的培養(yǎng)和爸媽的養(yǎng)育之恩。

此致

敬禮！

學(xué)生XXX

出國留學(xué)的介紹信14

xx院校：

　　您好!

　　我是柳導(dǎo)師，柳xx同學(xué)是我最欣賞的學(xué)生之一。她最吸引我的是她的學(xué)習(xí)天賦與上進(jìn)心，她是我見過的最聰明的學(xué)生，學(xué)習(xí)成績卓著，人文科學(xué)與自然科學(xué)同樣精通。更為難得的是她從不妄自尊大、自以為是，依舊刻苦地對待每一項(xiàng)學(xué)習(xí)任務(wù)，力爭成為整個團(tuán)隊(duì)中的。體現(xiàn)了她對自己和愛她的人負(fù)責(zé)的態(tài)度。

　　中國有句俗話：“梅花香自苦寒來”，經(jīng)過她持之以恒地付出，她的語言表達(dá)能力、活動的組織能力、與人的溝通能力、獨(dú)立研究能力都非常突出，連續(xù)獲得學(xué)校三好學(xué)生。特別是對英語，她具有天生的天賦與逐漸培養(yǎng)起的熱情，據(jù)我所知，她的雅思成績非常高，并獲得許多中學(xué)生英語競賽的獎項(xiàng)。能在英語國家學(xué)習(xí)，是她很久以前的夢想，為此她早已經(jīng)作好了準(zhǔn)備。我總是情不自禁的`感慨：她說的英語與我說的漢語一樣棒!

　　她不光是我的學(xué)生，還是我的朋友。因?yàn)樗�的個性與理想深深的.吸引了我。她總是無私地為團(tuán)隊(duì)奉獻(xiàn)自己的聰明才智，主動為大家服務(wù)，任勞任怨，不計較個人得失，成為我們眼中的英雄。她又非常幽默樂觀，用她微笑傳遞給大家一天的好心情。她又是一名體育健將，長跑、游泳、野外探險是她生活的一部分，從中她的意志得到了鍛煉。我們交往非常愉快，她特別樂于與我一起分享她成長中的喜怒哀樂。還常常與我談?wù)撾娪八囆g(shù)和旅游，美國的文化與風(fēng)景深深地吸引了她，那里有她一個夢想。

　　真舍不得她離開祖國，但我尊重她的選擇，相信她會學(xué)有所成，正如我相信我們的友誼天長地久一樣。

　　介紹人：

日期：

出國留學(xué)的介紹信15

　　Dear Colleagues：

　　As a teacher in Department of Biology, Nankai University, a leading university in China, I am very pleased to take this opportunity to recommend one of my favorite students to your PhD program.

　　In September, 20xx, Miss Zhang was my students in General Biology, the first professional course they take in the field. She likes it very much. I teach her in an open and interactive manner, she is active and passionate about answering class questions. Miss Zhang is bright, energetic and enthusiastic girl who loves speaking out her own ideas. She never escapes from those points of which she is skeptical. Apart from that, she often puts forward her ideas upon questions and exchanges all of her innovate ideas with me after class.

　　Upon ending of General Biology course, I asked my students to write an essay upon their understanding of biology. I discovered Miss Zhang’s essay was so impressive and persuasive; her careful essay comes from dozens of references to Biology literatures. In essay Miss Zhang stretched out her creative thinking upon status quo of biological research and branches in the field of biology. All of this speaks to her creative and logical and scientific thinking capability. I am gladly to say that Miss Zhang has a clear understanding about General Biology, that comprehension has been reflected fully in her essay. Therefore Miss Zhang got a full point for her essay in her class, and other students took it as model essay for granted.

　　I believe Miss Zhang’s industriousness, passion and dedication will make her an ideal candidate you are seeking for your program, so I highly recommend her without any hesitation to you. And I will greatly appreciate it if you could accept her into your program.

　　Sincerely yours,

【出國留學(xué)的介紹信】相關(guān)文章：

出國留學(xué)介紹信11-12

出國留學(xué)介紹信英文12-13

出國留學(xué)介紹信（優(yōu)秀）02-25

出國留學(xué)介紹信（薦）03-19

學(xué)生出國留學(xué)的介紹信11-26

出國留學(xué)介紹信(精選8篇)11-11

出國留學(xué)介紹信（精選13篇）10-26

出國留學(xué)介紹信【大全11篇】12-27

出國留學(xué)介紹信（通用5篇）10-01

出國留學(xué)介紹信集錦15篇10-18