people是可數名詞還是不可數名?

例句：

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

你可以和其他在線的人聊天。

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

總的.來說，當今的老年人依然相對貧困。

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

她有一段時間曾幫助垂危的癌症患者。

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

批評的聲音不會阻止人們涌到影院觀看這部電影。

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後的人。