China and India are of the third world.
中国与印度同属于第三世界。
Workers and peasants are of one family.
工人和农民是一家。
四、“be of 形容词最高级”,相当于 be one of… .例如:
His temper is of the quickest.
他的脾气是最急躁的。
Mr Liu is of the best teachers in our school.
刘老师是我们学校最好的老师之一。
五、“be of 抽象名词( value, importance, use, help, interest 等)”相当于“be 该抽象名词相对应的形容词”。其中 of 表示“具备;具有”, of 不可以省略。例如:
They are of great help / very helpful to learners of English.
他们对英语学习者来说是很有帮助的。
The press conference seems of great importance / very important.
这个新闻发布会看来很重要。