Superman; Lois Lane; Bizarro; Bizarro-Lois Lane; New Bizarro
Bizarro keeps the real Superman from revealing to Lois that she has been proposed to by Bizarro's duplicate, whom he calls New Bizarro, with a kryptonite meteorite, but Lois realizes New Bizarro is not the true Man of Steel. But New Bizarro doesn't give up easily, and the duplicates fight each other. Bizarro seeks out Superman's help and destroys the kryptonite, turning it into a dust cloud which destroys New Bizarro. Bizarro resumes courting Lois, until Lois creates a duplicate of herself so that Bizarro can have his own Bizarro-Lois.
Supergirl [Kara Zor-El; Linda Lee]; Superman (behind-the-scenes); Tommy Tomorrow (as a child, earliest chronological appearance); Mr. Tomorrow (introduction); Mrs. Tomorrow (introduction); Jik of Mars
Supergirl takes her first flight across the time-barrier from 1959 into the future, about a hundred years hence. She secretly observes a brilliant young orphan named Tommy on an asteroid orphanage. Tommy is told by the headmaster that a scientist and his wife have asked to adopt the boy with the best scientific mind, and he has been chosen. Supergirl ensures that the couple, the Tomorrows, make it to the orphanage successfully.