Be of Structure

•  be of + age, size, colour, weight, height, price, opinion, shape, kind, way. 说明主语的特征 , of 表示 ” 具有 ” 之意 , 有时可省去 .

•  They are both of middle height.

•  When I was your age, I was a teacher.

•  These flowers are of different colours.

•  Tom is of a different way of thinking.

•  Be of + 物质名词 , 表示主语是由 某种材料制成 或某成分构成 , 相当于 be made of, be built of, be made up of.

•  The necklace is ( made ) of glass.

•  The bridge is (made ) of stone.

•  Our class is (made of ) over 50 students.

•  Be of + value, importance, use, help 等抽象名词 , 表示 ” 具有 ”, “ 具备 ” 等意思 ; of 不能省 , 这一结构相当于 ” be + 该抽象名词相对应的形容词 .

•  They are of great help/very helpful to learners of English.

•  But in fact sports and games can be of great value/ very valuable.

•  The book is of no use./useless to me.

•  It is of great importance/ very important to study English.

•  His theory proved of importance.