The answer to this question is 3-D references.
3-D references usually contain same cell range on several different sheets. A 3-D reference is often used so sveral worksheets could follow a certain pattern when you put same data. This will make you able to input it faster rather than have to do it over and over again.
They collapsed. Black Friday, known as the beginning of the Great Depression.
Yellow fever.
after the Spanish War, the most caused deaths by 80% was of yellow fever.
