1) Celtic mythology encompasses the folklore and legends of the Celtic peoples across Europe, particularly in regions like Ireland, Scotland, and Wales. It features deities like Morrigan, Cernunnos, and Brigid, and delves into themes of nature, magic, and the heroic exploits of legendary figures like Cu Chulainn.

2) 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.

3) The shortest verse in the Bible is "Jesus wept" (John 11:35).

4) The Yangtze River, also known as the Changjiang River, is the longest river in Asia and the third-longest in the world, stretching over 6,300 kilometers (3,915 miles). It holds immense cultural, historical, and ecological significance for China and the surrounding regions.