题目内容：

______,they went to the playground.
a.Their homework finished b.Their homework was finished
c.Their homework being finished d.Their homework had been finished
独立主格结构,但是为何选A 其他项错在哪?

优质解答

独立主格结构为名词+分词（现在分词或过去分词）,意思是作业完成了,他们去了操场.c 表示正在进行,不选.b,d 都是完整的句子而后面又没有连词连接,所以不选