⼈:boy, girl, man, woman, etc.
(男孩,⼥孩,男⼈,⼥⼈等)
物:desk, pen, computer, mouse, etc.
(桌⼦,钢笔,电脑,⿏标等)
抽象概念:happiness, misery, success, failure, etc.
(幸福,痛苦,成功,失败等)