Answer:
For the first rehearsal, us knowing our lines was more important than saying them with expression.
Explanation:
In the given example, you need to choose the correct form of the pronoun we.
We is the first-person plural personal pronoun.
Us is the accusative form of the pronoun we, which means that it is usually used as the object of the sentence.
Our is the possessive form of the pronoun we.
The form that should be used in the given sentence is us. We can ask: What was important? Us knowing our lines. This construction shows us that it's important for the subject(s) to know their lines in the eyes of someone else. It can be important for them, as well, but the emphasis is on someone else. For example, the person leading the rehearsal could've told them to learn the lines without working on the expression, and that's why it's important for them to know them.
