1) The term "bull market" refers to a period of rising stock prices, while a "bear market" refers to a period of falling stock prices.

2) The game of basketball was invented by Dr. James Naismith in 1891 and has since grown into a global sport played at both amateur and professional levels.

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

4) The Sydney Opera House, situated in Sydney, Australia, is an iconic architectural masterpiece and a UNESCO World Heritage site. Its unique design, resembling sailboats or shells, has made it one of the most recognized and photographed landmarks in the world.