The girls are bored at school when Nasuno announces that she bought an art museum. They immediately head there to check out the art, but the objects on display aren't what they were expecting.
But it's more fun than hitting 
your knees to test your reflexes.
Divierte más que probar
tus reflejos con las rodillas.
Mas é mais divertido que bater no 
joelho para testar os seus reflexos.