1) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

2) The smallest unit of time is known as a zeptosecond, which is equal to one trillionth of one billionth of a second.

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) Beyoncé, full name Beyoncé Giselle Knowles-Carter, is a highly influential American singer, songwriter, actress, and businesswoman. She rose to fame as a member of the group Destiny's Child and has since achieved success as a solo artist.