1) The development of the World Wide Web Consortium (W3C) and web standards has ensured interoperability and compatibility across different web browsers and devices.

2) The world's first car radio was invented in 1929.

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

4) Robert Downey Jr. is an American actor known for his portrayal of Iron Man in the Marvel Cinematic Universe. He has also starred in films such as "Sherlock Holmes," "Chaplin," and "Tropic Thunder," and has received critical acclaim and commercial success for his performances.