people是可数名词还是不可数名?

例句：

1、You can chat to other people who are online.

你可以和其他在线的人聊天。

2、As a group, today's old people are still relatively deprived.

总的.来说，当今的老年人依然相对贫困。

3、She spent a period of time working with people dying of cancer.

她有一段时间曾帮助垂危的癌症患者。

4、The criticisms will not stop people flocking to see the film.

批评的声音不会阻止人们涌到影院观看这部电影。

5、I picked first all the people who usually were left till last.

我先挑出了所有通常留到最后的人。