26.on sale与for sale
for sale(个人所有物)“出售的”“待售的”，a house for sale房屋出售，not for sale(告示)非卖品。He put his car up for sale.他把汽车拿出来卖。on sale“销售中”“上市”“廉价的”“特价的”，如：They sell eggs on sale today.今天那家店鸡蛋大减价。on sale多指商品性质的东西。The summer wear is on sale.夏装正在销售。
27.all together与altogether
all together是一个形容词短语，多表示其原义，“所有的人在一处，同时在一起”。如：Today we are all together for the Spring Festival.因为春节，今天我们都聚集在一起了。altogether是个副词，表示“总共，完全”，如：How much is it altogether?这一共多少钱?
28.invent与discover
invent指创造发明以前不存在的东西或方法。如：Bell invented the telephone.贝尔发明了电话。invent还可指“虚构”或“捏造”一个情况。如：He invented an excuse for being absent.他捏造了一个缺席的借口。而discover则指发现不为人们所知但实际存在的事物。如：Do you know who discovered America?你知道是谁发现美洲的吗?I discovered that she was a good cook.我发现她很擅长烹饪。
29.contain与include
两词都有“包含”的意思。区别在于：contain可用于表示包含所含之物的全部或部分(have or hold within itself);而include则只能用于表示所包含之物中的一部分(have…as part of a whole)，如：The parcel contained a dictionary.那包裹里装的是一本字典。Does the price include postage?这价钱包含有邮费吗?另外，contain有“克制，抑制”之意。如：She could hardly contain her excitement.她抑制不住内心的激动。与include有关的including, included用法如下：We all went to the museum, Lily included.我们去了博物馆，莉莉也去了。The band played many songs, including some of my favourites.乐队演奏了很多曲子，包括我最喜欢的几首。
30.job, work, labour与task
这四个词都有“工作”的意思，其差异如下：
①job是可数名词，work是不可数名词，一般情况下可通用。如：His job (work) is as a teacher.他的职业是教师。但下面情况不可通用，如：I heard he changed jobs.我听说他已换了许多工作。I go to work (at) 7∶20.我七点二十去工作。He has a good job in a bank.他在银行里有个好职业。out of a job/out of work失业。
②labour一般指体力劳动，work泛指体力或者脑力劳动，如：It took many months of labour to build the house.建筑这房屋花了好几个月的劳动。The majority of men earn their living by physical labour.大多数人靠从事体力劳动谋生。
③task多指困难的或令人疲倦的工作，如：It’s a difficult task.这是一件(令人)困难的工作。Mary’s task is to tend the children.玛丽的任务是照料孩子。