being done和done用法的疑问

问题描述:

being done和done用法的疑问
Being examed twice a year is a basic rule.这句用being done为什么不能用done?

只有动名词才可以做句子的主语呢,被动不行在这里,put到第一个逗号的这一部分是做独立主格的,而独立主格一般用被动,表状态“独立主格结构”是由名词或代词作为逻辑主语,加上分词、形容词、副词、动词不定式或介词短语作为逻辑谓语构成。这种结构在形式上与主句没有关系,通常称为“独立主格结构”。例如The meeting being over, all of us went home. 开完会后我们都回家了。the meeting being over相当于when the meeting was overHer work done, she sat down for a cup oftea. 她干完了活,坐下来喝茶。herwork done相当于when her workwas done