1) The concept of separation of powers, as articulated by French philosopher Montesquieu, refers to the division of government responsibilities into distinct branches, such as the executive, legislative, and judicial, to prevent concentration of power.

2) The Treaty of Versailles, signed in 1919, officially ended World War I and imposed heavy penalties and reparations on Germany.

3) The word "oxygen" contains two vowels: O and E.

4) The International Monetary Fund (IMF) and the World Bank are international financial institutions that work to promote global financial stability and economic development.