同义词辨析

implement 表示采取实际措施使协定、合同、计划、政策等得以“贯彻”，“执行”。如：
Both countries did their best to implement the bilateral treaty. 两国都努力执行双边协定。 Donations are neede to implement this child-care program. 需要公众捐赠才能实施这项儿童保护计划。 They would like to see these policies implemented in the next parliament. 他们希望看到下一届议会能执行这些政策。
４. smell, taste和flavour的区别 (1)smell既可作动词，也可作名词。作动词时，表示“用鼻子嗅，感觉，体验”等意思。作名词时，意思市“嗅觉，刺激嗅 的气味。 I could smell that the milk was not fresh. This flower has a stronger smell than others. (2)taste也可作动词和名词，作动词时，指“尝一尝，尝出；吃（喝）一点儿；有某种味道”。作名词时，意思是“味觉， 道；尝一小点儿；趣味，情趣；爱好”。 I always taste the dish before it is served on table. She was ill, so she couldn't taste anyting at all. (3)flavour译为“味道（指舌头能感觉出来的味道）；味浓，味香”等等。还可用作动词，意思是“添加味道”。 There is a strong flavour of cheese in the room. Mother flavoured the cake with chocolate.
同义词辨析:
enforce,implement,carry out,execute
四个词语都可作“实施”，“执行”解。
enforce 表示职能部门采取强制手段使法律、秩序、合同、协定等得以“遵守”或“实施”。如：
The police must enforce laws. 警察必须实施法律。 Teachers enforce the rules of the school. 教师执行学校的规章制度。 U.N. troops were sent there to enforce the truce. 联合国部队被派往该地执行停战协定。
Once published, the novel will be very popular.
２.since与for的区别 since与for作介词都表示“持续一段时间”，它们都可用于完成时，在句子中作时间状语，但是since往往与表示时间 的短语连用，侧重句中动作开始的时间。而for常常与表示一段时间的短语连用，强调的是句中动作持续的时间长短。 I have not seen him since last week. We've not seen each other for ages.(夸张用法) He has stayed here for two weeks.
execute 含有圆满成功之义。表示“执行计划(或命令)”时常可与implement或carry out换用。表示“执行法律”时可 与enforce换。execute亦用于指“执行(某人的)遗嘱，系法律用词。如：
That plan was promptly executed/carried out/implemented . 该计划立即得到实施。 The nurse exected/carried out the doctor's orders. 护士执行医生的命令。 Congress makes the laws;the President executes/enforces them. 议会制订法律；总统执行法律。 He asked his brother to execute his will. 他要自己的兄弟来执行遗嘱。
carry out 是个较通俗的词语，其含义与implement相似，表示“执行计划(或协议、政策、命令)”等。 如：
The director said that they should carry out his advice. 主任说他们应将他的意见付诸实施。Fra Baidu bibliotekDid you have any difficulty in carrying out your plan?. 你们在执行计划的过程中有过什么困难嘛? He was simply carrying out the instructions he had received. 他只不过是在执行他所接到的命令。
单词辨析 1.once的用法
（１）用作副词表示： a.一次。如：He's been here once. Once a week.每周一次。 b.以前，从前。如：They were once friends, but now they are enemies.z once常用在词组里，如： at once立刻，马上；同时。如：They all spoke at once, but I heard nothing at all. once in a while偶尔，不时地。如：Once in a while he'll come to visit us. once more, once again又，再次，再来一遍。如：Once more, please. once upon a time从前，很久以前（常用来开始一个故事）。如：Once upon a time there was an old man. （２）作连词用，表示“一旦，只要”等意思，用来引起时间状语（从句）。如：
He is not worthy to be chosen monitor of the class.（后跟不定式）
７.either...or和neither...nor的区别 either和neither都可用作限制性形容词、代词、副词和连词。either是肯定用法，意思是“二者之一，二者中的任何 个”，而neither是否定用法，意思是“二者中哪个都不。 (1)作前置形容词，修饰限定其后单数（概念）的名词或代词。如： There are many big trees on either side of the street. Neither way to the station is near. 作这种用法时，注意either与both的区别：either修饰单数名词，both修饰复数名词。 (2)作代词，用来代替所指两个事物中的“任何一个”，或者“一个都不”。如： He's read the two novels, but he does not like either. He has heard of neither of the books. (3)作副词，意思是“也”，“也不”。如： I did not go to the meeting, and my wife did not either. I did not see him. Neither did I. 注意：这两个词都用在否定句中，用neither时句子需要倒装。too也是“也”的意思，一般用在肯定句的句末，而且其 应有逗号隔开。 (4)用作连词是时，往往构成either ...or和neither...nor这样的结构，表示，“要么....要么”和“不...，也不...”的 意思。如： Either you or I am to go to the theatre. He' been to neither Beijing nor Xi'an. 注意：用这两个结构时，所连接的两个部分必须是相应的内容，在句子中作同样的成份。这两个短语结构作主语 语应该与其相邻的部分保持一致，这也是所谓“相邻原则”。
３.journey, trip, tour和voyage的区别 (1)journey通常指“从一个地方到另一个地方所花费的时间和所走的距离”，常指陆上旅行，因而译作“旅程，旅途”。 They had a long train journey last month. (2)trip指“旅行，游览”。 He planned to make a trip to Asia, but failed to. (3)tour即可指“短期的旅游，游览”，也可指“周游，漫游”。 We went on a guided tour around the castle. (4)voyage意义与journey相近，但它指“海上航程”。 When I graduate, I will make a long sea voyage.
５. pack, package和packet的区别 三者均可作名词，指“包，捆，扎”。 (1)pack常指“背包（很多东西捆在一起或装在一起）”。 (2)package一般含有“一包东西，一个包裹”的意义，通常指“较大一些的包”，在美语中也可与packet互换。 (3)packet指“小包，小包裹”，美语中可用pack. The old man carried some food and water in a pack on his back. The teacher entered the classroom, carrying aa large package of books under her arm. She bought a packet of cigarettes in the shop. pack和package还可作动词。pack的意思是“打行李，打包裹”，而package指“把东西打成包”。 ６.worth和worthy的区别 (1)worth可作介词和名词。作介词是，有下列意思； a.值，价值。如：The new tupewrite is wroth 200 yuan. b.值得（此时worth后可跟名词或代词，也可跟不带宾语的及物动词或短语的动名词。跟动名词时，句子的主语实 动名词或动名词短语的逻辑宾语。如： He felt it was not worth the effort. The risk is worth taking. worth作“值得”理解时，后面还可跟不及物动词或带宾语的及物动词或短语的动名词。此时句子主语往往是it，句子 构是这样的：It + be worth + doing ...做某事很值得。如：It isn't worth listening to him. (2)作名词，表示“价值（一定数量钱的东西）；需要或维持（一定时间的工作或食物等）”如： There is about $5000 worth of furniture in that big house. There is still another two hours worth of fight to the country. (3)worthy用作形容词，表示“有价值的，有意义的，有能力的，有出息的，值得尊敬的”。如： Tom is the worthiset winner of the race.(作前置定语） Mary is a leader worthy of great respect.(做后置定语） Everyone believes that the cause is worthy.(作表语）