Answer: the sacrifice of unknown people who fought for equality
Explanation: What Abraham Lincoln's Gettysburg Address, what President Lincoln and Martin Luther King's Nobel Prize acceptance speech share is the recognition of the sacrifice of unknown people who fought and still fight for equality.
The Gettysburg Address was delivered by Lincoln in 1863, in the Soldier's National Cemetery, a cemetery for Union soldiers killed at Gettysburg. In the Nobel Peace Prize acceptance speech, 1964, King speaks to the hard-working people who fight for civil rights and to make equality possible.
Repetition helps exaggerate a point that the author is trying to convey. It highlights the main idea of what that character in the story is trying to let readers understand when stating such phrases.
