大学英语：In every cultivated language there are two great classes of words which

　　1. In every cultivated language there are two great classes of words which， taken together， make up the whole vocabulary.

　　class在本句中的意思是“种类”，相当于type， category.如：

　　1)It is very difficult to meet the needs of various classes of readers.(要满足各种读者的需要十分困难)

　　2)How many classes are you going to divide these books? (你打算把这些书分成几类?)

　　class 还常用来表示“等级”，如：a second-class hotel (二等旅馆);

　　an economy-class ticket (经济舱票);fly first class (乘头等舱航空旅行)。

　　class 也可以用动词用，意思是“把 …分类;把…看作”，如：

　　1)At 19 you are still classed as a teenager.(到了十九岁，你仍旧是青少年。)

　　2)He was classed as a genius (他被看作为天才)

　　make up 在本句中的意思是“组成、构成”，请看例句：

　　1)Twenty-six boys and twenty-four girls make up the class (二十六名男生和二十四名女生组成了这个班)

　　2)Twelve doctors made up the medical team (十二名医生组成医疗队)

　　用被动语态时则应用be made up of，如：

　　This engine is made up of 490 parts (这台发动机是由四百九十个部件装配而成的)

　　taken together 过去分词短语做后置定语，对中心词做一些附加说明，相当于一个非限定性定语从句，要用逗号和中心词隔开，如：

　　All the letters in the drawer， written in pencil， are from my brother.(抽屉里的这些用铅笔写的信都是我弟弟写的。)