Just in case people might have missed it, make sure to check the course content tab to get a link to the GDScript format strings.
I assume just the script is enough to know what it makes:
extends Node2D
var prompt = ["person", "ate", "blue", "dragon", "toe", "tired"]
var story = "Once upon a time, there was a %s who %s a %s %s. Afterwards she hurt her %s and became very %s."
func _ready():
print(story % prompt)
