I'd have finished it, some of them before we'd even be assigned them, and I'd read up the bit we were going to do that day, have my delivery and timing, have my voices all lined up.
Our teacher I think wanted everyone - reading - each - word - at - a - time - like - this, but I couldn't be bothered with that crap. Make the words live! Make the people real!
And now some forty-some years later, I hear my six-year-old reading his books in his bedroom out loud, trying different voices for different characters until he's got one he likes. I'm going to get so many emails from his teacher, aren't I? But I'm not ever going to tell him to stop.
I really, really hope they're worrying unnecessarily! I think it's better to find out early if a teacher is going to have an issue with things like that.
They will grow out of it eventually. Most of them anyways.