Extract the dates from the following paragraph: "The 20th (twentieth) century began on January 1, 1901 (MCMI), and ended on December 31, 2000 (MM).[1] The 20th century was dominated by significant events that defined the modern era: sixth mass extinction, Spanish flu pandemic, World War I and World War II, nuclear weapons, nuclear power and space exploration, nationalism and decolonization, the Cold War and post-Cold War conflicts, and technological advances. These reshaped the political and social structure of the globe."