elder — older senior
material — substance stuff matter
individual — single separate personal
reason — cause logic explanation
underwater — deep-sea
average — [普通的]：usual ordinary passable
[平均的]：middle medium
regulate — [管理]：manage direct handle control
[调整]：adjust remedy rectify correct
although表转折-----despite, but, however,in fact,indeed
possess拥有-----own,have,hold,control,maintain,occupy
promotion促进，提升，提拔-----advancement,forwarding,improvement,rise,betterment,progress
negotiation谈判，协商，准备-----arrange,settle,mediate,talk over
engage从事，占去,卷入-----involve,entangle
benefit利益，得益-----capitalize,profit
settle定居-----occupy,inhabit,live in,locate,conolize
immigrants移民-----people from other countries
employment就业-----job,career
to keep a record记录-----to keep a diary
action行为-----what they did
lapse错误-----error,fault,slip,
research研究，调查-----delve,search,study,investigate,inquire,explore,look into
layoff解雇-----unemployment,downsizing in workers
associate联合-----join,connect,unite,combine
opponent对手-----enemy,foe,adversary,competitor,rival,saboteur
argument争论-----dispute,controverse
oppose反对-----counteract,fight,struggle,resist,conflict with,refuse
realize认知，了解-----understand,grasp,conceive,comprehend,appreciate
以上的同义替换不管是破折号之前的单词还是之后的单词都是在真题里面出现过的单词，其中不乏一些高频词汇。关于其他的高频词汇我会在课堂上遇到一个讲一个，另外，在记忆这些同义替换的单词的时候不要只记我所提供的词性，在做题时遇到词根一样二词缀变换了的单词也属正常，下面是关于各位同学在做15选10时及其重要的词缀介绍：
1、名词后缀：
-ability,-ibility,(可--性，易---性)-acity,-acy,-cy(性质，状态，情况)，-ade(动作，动作的结果),-age(集合名词，总称),-ancy,-ance,-arity,-ence,-ency,-esis(医学名词和疾病名称)，--ety(性质，状态)，-hood,(身份，时期，资格，性质)-ing(行为，情况),-ism(主义，宗教，制度),-icity,-ity,-ment,-tion,-ry,-sion,-logy(学术);
2、形容词后缀：
-ble,-ible,-ant,-ar,-ent,,-ic,-ful,-iac,-cal,-ish,-tious,-ive,-less,-ory,
3、副词后缀;
-ly,-wise