高中英语语法问题，独立主格结构

The exam to be held tomorrow,是动词不定式的独立主格结构

表示 一次性动作 将要发生
这与分词的独立主格结构 用法 和意思 不一样
不定式“独立主格结构”
在“逻辑主语+动词不定式”结构中，动词不定式和它前面的名词或代词存在着逻辑上的主谓关系。这种结构也可用一个从句或并列分句来表达。
1．动词不定式用主动的形式
在独立主格结构中，动词不定式和它前面的名词或代词存在着逻辑上的主谓关系。
His mother to come tonight，he is busy preparing the dinner.他母亲今晚要来,他正在忙着准备饭菜。（= As his mother is to come tonight, he is busy preparing the dinner.）
——will you go to the comcert tonight 你今晚去听音乐会吗？
——sorry.So many exerise-books to check,I rially can't afford any time.对不起，有这多的作业要批，我真的抽不出时间。（＝Because I shall check so many exercise-books tonight,I really can't afford any time.）
The four of us agreed on a division of labour,each to translate a quarter of the book.我们四人同意分工干，每人翻译全书的四分之一。（＝The four of us agreed on a division of labour and each is to translate a quarter of the book.）
Many trees,flowers,and grass to be planted,our newly-built school will look even more beautiful. 种上许多的树，花和草后，我们新建的学校将看上去更美。(=If many trees,flowers,and grass are planted,our newly-built school will look even more beautiful.)

你仔细比较以上几种独立结构，有区别，你这个句子考试将要举行，带有将来时，你发现没有其他几种都不能表示将来