1. composition: a piece of written work that children write at school. could be just 50–100 words, often used for school work（多指學(xué)校里老師給學(xué)生的作文練習(xí)，長(zhǎng)度較短）。
Eg. Little Martha did her first composition in school today. It was called ‘My family’. 小瑪莎今天在學(xué)校完成了她的第一篇作文。題目是“我的家”。
2. essay: a short piece of writing on one particular subject written by a student. longer than a composition, more serious, hundreds or thousands of words （學(xué)生就某門課程、某個(gè)題目所寫的論說(shuō)文，短文。包括考研英語(yǔ)大作文的題目也是要求寫一篇essay。廣義上來(lái)講，指任何一種非小說(shuō)性的，篇幅不長(zhǎng)、結(jié)構(gòu)簡(jiǎn)練的文章，如論說(shuō)文、報(bào)道、評(píng)論、諷刺性雜文等。專業(yè)essay代寫品牌：essay.lxws.net）
Eg. The teacher gave us the title of this week’s essay today. We have to write 1,000 words on the topic of ‘If I ruled the world’ and hand it in next Monday. 今天老師給了我們本周作文的題目。我們必須以“如果我統(tǒng)治了世界”為主題寫1000字，并在下周一交。
3. assignment: a task or piece of work that you are given to do, especially as part of your studies. a long essay, often part of a course, usually thousands of words （布置的作業(yè)、任務(wù)。比essay更長(zhǎng)，通常有幾千字）
Eg. At the end of this course, you have to do a 5,000-word assignment which will be assessed, and the grade will contribute to your final grade. 在本課程結(jié)束時(shí)，你需要完成一個(gè) 5,000 字的作業(yè)并被評(píng)估，成績(jī)將計(jì)入你的期末成績(jī)。
4. dissertation: a long formal piece of writing on a particular subject, especially for a university degree. a long, research-based work, perhaps 10–15,000 words, for a degree or diploma. （書面語(yǔ)用詞，指獨(dú)立研究后所寫的較為詳細(xì)的專題文章，學(xué)位論文。）
Eg. I think I’ll do a study of people’s personal banking habits for my MSc dissertation. It has to be about 12,000 words. 我想我會(huì)在我的碩士論文中研究人們的個(gè)人銀行習(xí)慣。它大概需要 12,000 字。
5. thesis: a very long, original, research-based work, perhaps 80–100,000 words, for a higher degree (e.g. PhD) a long piece of writing based on your own ideas and research that you do as part of a university degree, especially a higher degree such as a PhD. （很長(zhǎng)，原創(chuàng)，基于研究，闡述學(xué)術(shù)觀點(diǎn)的學(xué)位論文，通常指博士畢業(yè)論文）
Eg. His PhD thesis was 90,000 words long and was on the history of US place names. 他的博士論文長(zhǎng)達(dá) 90,000 字，是關(guān)于美國(guó)地名的歷史。
6. paper: a long, formal piece of writing about an academic subject. an academic article about a particular subject that is written by and for specialists （正式用詞，多指在學(xué)術(shù)刊物上發(fā)表或在學(xué)術(shù)會(huì)議上宣讀的專題論文，也指高等學(xué)校的學(xué)期論文，或?qū)W校里的作文練習(xí)。）
Eg. He just published a paper in the journal Nature analyzing the fires. 他剛剛在《自然》雜志上發(fā)表了一篇分析火災(zāi)的論文。
7. article: a piece of writing that is published in a newspaper or magazine （多指在報(bào)刊、雜志上發(fā)表的非文藝性的文章，包括新聞報(bào)導(dǎo)、學(xué)術(shù)論文等。）
Eg. According to an article in The Economist the drug could have side effects.《經(jīng)濟(jì)學(xué)人》雜志上的一篇文章講到這種藥可能有副作用。
8. report: an official document which a group of people issue after investigating a situation or event. （在做對(duì)某種情況或事件做調(diào)查后寫出的調(diào)查報(bào)告，情況匯報(bào)）
Eg. A report by the Association of University Teachers finds that only 22 per cent of lecturers in our universities are women. 大學(xué)教師聯(lián)合會(huì)發(fā)表的報(bào)告發(fā)現(xiàn)只有22%的大學(xué)講師為女性。