3.用在复数名词之前

(1)表示一类人和事物。

Those young men are teachers，not students．

那些年轻人是老师，不是学生。

Axes are sharp-edged tools for chopping wood．

斧子是砍木头的锋利工具。

(2)泛指不定量的某类人或事物。Don't stand in the doorway．There are people waiting to come in．不要站在门口。有人等着要进来。

提示：

我们能在上句中的people之前加上some，因为这里是泛指不定量的“人们”，但不能在Those young men are teachers，not students句中的teachers和students之前加some，因为在这里是泛指“教师”和“学生”的类别。

Pencils，pens and sheets of paper were all over the table．桌子上摆满了铅笔、钢笔和一张张的纸。

The streets were clean and shaded with trees．

街上很干净，绿树成荫。

提示：

但是定冠词与复数名词连用时，表示在某种情况下该类事物的全体。请对比:

We are students of Class One．(指部分，不定量)

We are the students of Class One．(指全体)

Doctors were badly needed at the front．(泛指，不定量)

Give me a list of the doctors．(特指，指双方都知道的全体医生)