note 是可数名词吗?

在表示声明和注意时 不可数
以下的可数
笔记;记录[C]
He never took notes in class.
他上课从不记笔记.
2.注,注释[C]
3.便条;(外交上的)照会[C]
Tom opened the note from his cousin.
汤姆打开了表兄写给他的便条.
4.纸币;票据[C]
He sent me four fifty-dollar notes.
他寄给我四张五十圆面额的钞票.
5.音符[C]
6.口气,调子[S][(+of)]
There was a note of warning in what he said.
他的话带有一种警告的口气