______,they went to the playground.a.Their homework finished b.Their homework was finishedc.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?
问题描述：
______,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?
答
b,d都是完整的句子不能用逗号连接后边的话,独立主格就只能是A了
答
独立主格结构为 主语+分词，排除b.d。作业被完成且在去操场之前，排除c（c是代表被动进行）。
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
答
独立主格结构其中的一种形式是“名词+分词（现在分词或过去分词）”。纵观四个选项，只有a. Their homework finished 符合。