All 15 of the U. S. Presidents who served between 4 March 1885 and 9 August 1974 passed away during the 20th century.
(Several of the other copies of this question show the answer to be 16. To those who believe the answer to be 16 I offer the following observation: Grover Cleveland was neither two people nor did he die twice.)
The Unfinished Twentieth Century has 144 pages.
Peasant Wars of the Twentieth Century has 328 pages.
36,525
"In the twentieth century" - The prepositional phrase in this sentence is "in the twentieth century."
12 were added
There were 12 amendments added to the constitution in the 20th century.
Flat
Zero!
58
3
true
sale of crude oil