mean: now usually in the plural means, is very general and may apply to anything or anyone that serves an end: had no ~s of traveling but his own two feet.    （means有2个意思 1、钱财the money that someone has，如a woman of means富有女人，she was living beyond her means入不敷出，开销比收入大  2、手段a way of doing or achieving something，如trains, buses, and other means of transportation火车汽车和其他交通手段，如the property was obtained by illegal means非法手段获得的财产，如for her, marrying a rich man is just a means to an end对她而言，嫁给富人只是实现目的的手段，如succeeding by any means用任何手段取得成功，如have no means of support无依无靠；另外词组by all means表示certainly当然，by no means表示in no way, not at all绝不）    （end目的，强调希望取得的结果，和means手段相对stresses the intended effect of the action often in distinction or contrast with the action or the means as such，如will use any means to achieve his end为达目的使用任何手段）  


instrument: as applied to persons, implies a secondary role, sometimes as a tool, sometimes as a dupe: used him as the ~ of her ambitions; and, as applied to things, is likely to suggest a degree of fitness or adaptation for use as a tool: politics, a powerful ~ for change.    dupe指利用对方不谨慎来欺骗，暗指受骗的人不谨慎，dupe这里作名词，表示被欺骗的人   （又如an instrument of fate受命运摆布的人（工具），an instrument for change促成变革的工具，如the law is not the best instrument for dealing with family matters法律并不是处理家庭问题的最佳工具）    fit适合adapt适应


agent: applies to a person who acts to achieve an end conceived by another: dealt with a real estate ~; or to a thing that produces an immediate effect or definite result: salt, an ~ in the melting of ice.   conceive设计设想          (如a theatrical/literary/insurance/stock transfer agent剧院经纪人/文稿出版/保险/股票交易代理人，enemy agent敌方特务，即间谍，cleaning/oxidizing agents去污剂/氧化剂)   (agency表示办事机构公司，如an advertising/employment/dating agency广告公司/职业介绍所/婚介所，CIA中情局。来自词根AG表示act做，如agenda日程agitate激动agent代理agile敏捷)


medium: applies to a usually intangible means of conveying, transmitting, or communicating: resorted to sign language as a ~ of communication.  tangible有形的实体的   （又如money is a medium of exchange是交换手段（媒介），media媒体指电台电视台报社等将信息传送给公众的机构TV stations, radio stations, and newspapers through which information is communicated to the public ，如she feels the media is/are ignoring the issue她觉得媒体忽视了这件事；传统四大媒体是广播电视报纸杂志，网络是一种新的媒体；在美国media还表示媒体从业人员，如the event attracted a lot of media吸引了大量媒体人；信息的表现形式也可以叫媒体，文本声音图像视频也都称为媒体，如多媒体）


mean手段: 泛指用于实现目的的事物，instrument工具: 指人时表示被当作工具欺骗利用的人，指物时表示适合的工具，agent代理经纪、(化学)剂:  指代理他人事务的人，或具有特定功能的事物，medium媒介媒体: 指用于传输传送通信的手段，通常无形

记忆方法: 1）首字母MIAM排序成maim致残<==手段

         2）手段的意思是用于实现目的的mean something or someone necessary or useful in effecting an end.