Original sentence: A "Doctor-lite" episode, David Tennant only makes a small contribution to the episode as the Tenth Doctor.The episode instead focuses on the Doctor's companion, Donna Noble (Catherine Tate) and her encounters with the Doctor's previous companion Rose Tyler (Billie Piper)
Edited sentence: David Tennant only makes a small contribution to this "Doctor-light" episode as the Tenth Doctor.The story instead focuses on the Doctor's companion, Donna Noble (Catherine Tate) and her encounters with the Doctor's previous companion Rose Tyler (Billie Piper)