Antitrust law is an important law for restricting the operation of professional sports leagues.

反垄断法是影响职业体育联盟运营的重要法律。

youdao

The research methods of literature, comparison etc. were applied to analyzing the organizational model of professional sports leagues.

运用文献资料、比较等研究方法，对职业体育联盟的组织模式进行分析。

youdao

The methods of literature and comparison were applied to analyze the difference between European and American professional sports leagues.

运用文献资料法和比较法，对欧、美职业体育联盟的区别进行比较分析。

youdao

All these sports are American inventions and have developed wide support in schools,amateur and professional leagues.

VOA: special.2010.06.02

All 122 teams in North America's four major professional sports leagues have official Twitter accounts.

WSJ: Not Trending on Twitter: #ArizonaCardinals��Sports Teams With the Least Followers on Twitter

The NBA stands apart from other professional sports leagues because of the popularity of gaming with its athletes.

FORBES: Potential NBA Lockout Won't Impact New Basketball Video Games

The concept of game day jersey sponsorship is not new to the business of U.S. professional sports leagues.

FORBES: Jersey Sponsorships Likely Coming To U.S. Sports