He and Martha use the data tablet that came with Clark from Krypton to examine holographic records of Kryptonian history.
2.
Having seen footage from the data tablet that was in his spacecraft, Clark knows Luthor must have used similar methods to uncover these images.
3.
Superman, Brainiac 5, and Colossal Boy find the other Legionnaires and the crystal data tablet containing the false claims regarding Superman's origins.