Some do, some don't. Some require EMT certification or Paramedic licensure to take the test (bare minimum requirements). Some require one or both of those plus a firefighter 1 academy or firefighter 1 certificate. Some just require you to be 18 years old and have a high school diploma or GED.
Learn the French lyrics and English translation of the Flower Duet (a.k.a.  Sous le dÃ´me Ã©pais) from Delibes' opera, Lakme. Flower Duet Lyrics and Text Translation Search the site GO
There is another version of the source of the term. According to the 1892 fictional masterpiece by Han Bangqing called Sing-Song Girls of Shanghai, also known as Flowers of Shanghai, people in Shanghai called the women who performed in sing-song houses xian sheng (Chinese: åç) in Wu language.