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) J.K. Rowling's "Harry Potter" series of books has sold over 500 million copies worldwide and has been translated into 80 languages.

3) Orchids are one of the largest families of flowering plants, with over 25,000 species.

4) The Industrial Revolution led to significant urbanization, as people migrated from rural areas to cities in search of employment in factories.