Question: Shelby Cannon and David Adams, had what previous occupation?

Context paragraphs:
Helen Wood (television personality): Helen Wood (born 28 November 1986) from Bromley Cross, Bolton is a British reality television participant and journalist.  Wood is best known as the winner of "Big Brother 15" before briefly returning for "Big Brother 16" and for her previous occupation as a prostitute, involved in 2010 with England footballer, Wayne Rooney, and Jenny Thompson.

1993 Qatar Open – Doubles: Boris Becker and Patrik Kühnen won the title, defeating Shelby Cannon and Scott Melville 6–2, 6–4 in the final.

2001 Milan Indoor – Doubles: David Adams and John-Laffnie de Jager were the defending champions but only Adams competed that year with Marius Barnard.

1996 EA-Generali Open – Doubles: Francisco Montana and Greg Van Emburgh were the defending champions but they competed with different partners that year, Montana with Donald Johnson and Van Emburgh with Shelby Cannon.

1990 US Open – Mixed Doubles: Robin White and Shelby Cannon were the defending champions but lost in the second round to Zina Garrison and Rick Leach.

Leon Adams: Leon David Adams (February 1, 1905 – September 14, 1995) was an American journalist, publicist, historian and co-founder of the Wine Institute.  In 1958, Adams book "Commonsense Book of Wine" was published, which sought to bring table wine into everyday life in the United States.  His book "Wines of America", published in 1973, is considered the "most thorough work on the subject," specifically regarding the California wine industry.

2001 ABN AMRO World Tennis Tournament – Doubles: David Adams and John-Laffnie de Jager were the defending champions but only Adams competed that year with Marius Barnard.

Kadashman-harbe I: Kadašman-Ḫarbe I,inscribed in cuneiform contemporarily as "Ka-da-áš-ma-an-Ḫar-be" and meaning “he believes in Ḫarbe (a Kassite god equivalent to Enlil),” was the 16th King of the Kassite or 3rd dynasty of Babylon, and the kingdom contemporarily known as Kar-Duniaš, during the late 15th to early 14th century, BC.  It is now considered possible that he was the contemporary of Tepti Ahar, King of Elam, as preserved in a tablet found at Haft Tepe in Iran.  This is dated to the “year when the king expelled Kadašman-,” thought by some historians to represent him although this identification ( = Ḫarbe) has been contested.  If this name is correctly assigned to him, it would imply previous occupation of, or suzerainty over, Elam.

Shelby Cannon: Shelby Cannon (born August 19, 1966, in Hattiesburg, Mississippi) is an American retired professional tennis player.

David Adams (tennis): David Adams (born 5 January 1970) is a former professional tennis player from South Africa.  He turned pro in 1989.  During his career he won 19 doubles titles and finished runner-up an additional 33 times, including at the French Open in 1992.  He achieved a career-high doubles ranking of World No. 9 in February 1994.

Supporting paragraphs: Shelby Cannon David Adams (tennis)
Answer: tennis player