of+名词=adj

of+抽象名词=形容词.如a women of wealth/wisdom/courage=a wealthy/wise/courageous woman

be of+修饰语+抽象名词.比如

be of importance/help/use/significance=be important/helpful/useful/significant

这一结构可用于说明主语的性质,比如

This question is of importance.(=This question is important.)

baiIt is important to do sth.=It is of importance to do sth.