Answer:
Blank One: Quieres; Blank Two: Puedo; Blank Three; Volver
Explanation:
One: The tu form of Querer is Quieres, he's asking "do you want to ride bikes"
Two: The yo form of Poder is Puedo, saying "No, I can't"
Three: After "tengo que" you use an infinitve verb, in this case "volver"
