By pro I guess you mean MLS which is the first tier of American soccer, in that case it's 15 teams.
1
All depends on the club they support.
All do.
Chelsea
A normal professional player usually can play for many different teams. But, International players usually play for 2 teams - Their national team and Their Pro Football club.
They are 32 pro football teams in the NFL.
There are four pro baseball teams in Missouri
Some acronyms for U.S. Pro Soccer would include the USSF which stands for the United States Soccer Federation and there are also three professional soccer league divisions under the United States Soccer Federation. Division I, the strongest and highest division, is made up of teams from MLS or Major League Soccer. Division II is made up of teams from the NASL or the North American Soccer League. Division III, the weakest and lowest division, is made up of teams from the USL Pro, or United Soccer Leagues Professional Division.
professional soccer is teams that have the best players in the country or maybe even the world. you can become a pro soccer player if a scout thinks you're the best at playing soccer.
24 teams.
soccer is the sports that has most pro leagues. It even has a World cup.
there are 30 hockey teams in the nhl