You shouldn't skip lines.
Harry was in the play, and he was reading his lines for his part.
Harry wants to finish the preformance.
Harry reads the script perfectly, making sure to memorize every single line.
Harry skips a line he considers of low importance in scene 2.
Harry puts on a great performance for the play and the crowd loves it.
The other preformers miss the skipped line and instead reply to the skipped line.