15.of

(1)He is a man of humble origin.（来源） (2)I did it of necessity.（出于）

(3)The explosion couldn't have happened of itself.（表示原因） (4)The Indians robbed them of their possessions.（表示脱离） (5)She has the devil of a temper.（表示属性）

(6)Mary is an angel of a woman.（表示同位）