boundary | n. 边界；界线（侧重地图上正式标定的、双方遵守的边界，也可指较小行政单位间的界线） | The fence marks the boundary between my land and hers. |
border | n. 较宽的边缘，边界（多指国与国之间或两地区的分界处，即分界线附近的边缘部分） | We crossed the Mexican border into the USA. |
frontier | n. 国界，边界，边境；（尤指19世纪美国西部的）开发地区边缘地带，边远地区 | a frontier town/zone/post边陲小镇；边疆地带；边防站 |
rim | n. （圆形物体的）边，边缘 | The rims of her eyes were red with crying. |
verge | n. （道路、花坛等长着草的）边缘；某事即将发生的时候 | on the verge of war战争爆发之际 |
22.brief / concise / succinct
brief | a. 短时间的，短暂的 | The manager made a brief statement to open the meeting. |
concise | a. （文字等的）简要、精练（常含有保留主要部分的意思） | His letter was concise, omitting everything not pertinent to the job. |
succinct | a. 简明的，简洁的，简练的（尤指用词简练，除含有concise的意思外，还有经过压缩的或简化的意思） | succinct summary of the argument |
23.change / alter / vary / modify / turn / convert /transform
change | v. （一般用词）改变，变化（指任何变化，强调与之前不同） | Her life changed completely when she won the lottery. |
alter | v. （使）改变，更改，改动（注意此变化无法改变事物本质，变成另一事物） | Prices did not alter significantly during 2004. |
vary | v. （在一组类似的事物之间大小、形状等）相异，不同，有别（近义词：differ） | Prices vary according to the type of room you require. |
modify | v. 调整；稍作修改；使更适合（指细小的变化，尤其为了更符合某一目的而做出调整） | The software we use has been modified for us. |
turn | v. （使）变成，成为（较change通俗） | She turned a deathly shade of white when she heard the news. |
convert | v. （使）转变，转换，转化（改变物理或化学本质或某些特性，特别是在制造过程中） | The hotel is going to be converted into a nursing home. |
transform | v. 使改变形态（近义词：convert） v. 使改变外观或性质（侧重彻底且往往变得更好） | A new colour scheme will transform your bedroom. |
24.clear / plain / apparent / obvious / evident / manifest / distinct
clear | a. （一般用词）清晰易懂的；明白清楚的；不含混的（侧重易理解无疑惑，清楚明白） | She gave me clear and precise directions. |
plain | a. （一般用词）清楚的；明显的；浅白的（与clear可通用） | He made it plain that we should leave. |
apparent | a. 显而易见；明白易懂；显然（尤指容易观察到或理解的事物，强调显而易见或一想便知） | He is very unhappy, and it is apparent that he wants to leave now. |
obvious | a. 明显的；显然的；易理解的 | I know you don’t like her but try not to make it so obvious. |
evident | a. 清楚的；显而易见的；显然的（指根据事实成为显然的） | The orchestra played with evident enjoyment. |
manifest | a. （书面用词）明显的；显而易见的 | His nervousness was manifest to all those present. |
distinct | a. 清晰的；清楚的；明白的；明显的（易于被感官感受到） | There was a distinct smell of gas. |
25.common / ordinary / general / usual /universal
common | a. 常见的，普通的，不足为奇的（多指物） | Car accidents are a common occurrence. |
ordinary | a. 普通的；平常的；一般的；平凡的（多指物） | This was no ordinary meeting. |
general | a. 正常的；一般的；常规的（强调大多如此很少例外） | There is one exception to this general principle. |
usual | a. 通常的；寻常的；惯常的（强调惯常性） | She made all the usual excuses. |
universal | a. 普遍的；全体的；全世界的；共同的（比general语气更强，侧重对每个人或事物都适用，根本没有例外） | Such problems are a universal feature of old age. |
26.compel / constrain / force / oblige
compel | v. 强迫，迫使（指在法律、权力、力量或行动等的驱使下被迫而为） | His illness compelled him to stay in bed. |
constrain | v. 力劝，强迫（侧重施加约束力或有约束作用的影响，也指环境对人强加的影响迫使人去做某事，尤指受良心、情感等内在力里驱使去做某事） | As an artist he didn’t consider himself constrained by the same rules of social conduct as other people. |
force | v. 强迫，迫使（指用个人意志、权力、权威或暴力等，迫使他人改变看法或做本不愿做的事） | The thief forced her to hand over the money. |
oblige | v. 强迫，迫使（指由于生理上或道德上的需要，促使某人做某事，也指有权威的人或机构迫使某人做某事，还可指在特定情况下被迫作出的反应） | We are obliged to stop the car at a red light. |
27.complement / supplement / append
complement | n. 补充物（主要指补充不足使之完美） | Rice makes an excellent complement to a curry dish. |
supplement | n. 增补，补充，补贴（主要指额外增加） | One year after we made our report, we had to add a supplement to cover new events. |
append | n. 附加，添上或补充某事物（尤指文字） | The lawyer appended two more pages to the contract. |
28.component / element / factor / ingredient
component | n. 组成部分；成分（指一个整体的组成部分） | Tires, the engine, the body, and the seats are component of a car. |
element | n. 元素；组成部分，方面（指一个整体必不可少或固有的部分，强调一个复杂整体中最基本、最简单的元件、元素或成分等） | The elements hydrogen and oxygen combine to form water. |
factor | n. 因素，要素（侧重指原因） | Endurance is an important factor in success in sports. |
ingredient | n. 原料，成分，要素（含义笼统，既可指混在一起而本身没有变化的物质，如配料，又可指与别的物质混在一起，发生了变化的成分） | Flour, milk, butter and yeast are some ingredients in bread. |
constituent | n. 成分；构成要素（常可与component换用，指某一整体不可少的部分或成分） | Caffeine is the active constituent of drinks such as tea and coffee. |
29.comprise / compose / consist / constitute
comprise | v. 包括；包含；由…组成 | Our company’s product line comprises 2,500 different items. |
compose | v. （正式用词）组成，构成（一个整体） | The committee was composed mainly of teachers and parents. |
consist | v. （consist of sth.）组成，构成，由……组成 | The problem consists of two parts. |
constitute | v. 构成，组成 | Female workers constitute the majority of the labour force. |
30.concentrate / focus
concentrate | v. 集中（注意力），聚精会神（指把精力或注意力集中于某一事物上） | During exams, students concentrate hard on answering the questions. |
focus | v. 集中（注意力、精力等于...）（指把思想或精力等集中于某人或某事情上） | Please focus your minds on the following problem. |
