Answer the following question: Information:  - Cameron Howard Winklevoss ( born August 21 , 1981 ) is an American rower and entrepreneur . He competed in the men 's pair rowing event at the 2008 Beijing Olympics with his identical twin brother and rowing partner , Tyler Winklevoss . Cameron and his brother are known for co-founding HarvardConnection ( later renamed ConnectU ) along with Harvard classmate Divya Narendra . In 2004 , the Winklevoss brothers sued Facebook founder Mark Zuckerberg for $ 65 million , claiming he stole their ConnectU idea to create the popular social networking site Facebook . In addition to ConnectU , Winklevoss also co-founded the social media website Guest of a Guest with Rachelle Hruska .  - ConnectU (originally HarvardConnection) was a social networking website launched on May 21, 2004, that was founded by Harvard students Cameron Winklevoss, Tyler Winklevoss, and Divya Narendra in December 2002. Users could add people as friends, send them messages, and update their personal profiles to notify friends about themselves. Users were placed in networks based upon the domain name associated with the email address they used for registration.  - Tyler Howard Winklevoss (born August 21, 1981) is an American rower and entrepreneur. He competed in the men's pair rowing event at the 2008 Summer Olympics with his identical twin brother and rowing partner, Cameron Winklevoss. Winklevoss co-founded HarvardConnection (later renamed ConnectU) along with his brother Cameron and a Harvard classmate of theirs, Divya Narendra. In 2004, the Winklevoss brothers sued Mark Zuckerberg for $65 million, claiming he stole their ConnectU idea to create the much more popular social networking service site Facebook.  - The 2008 Summer Olympic Games, officially known as the Games of the XXIX Olympiad and commonly known as Beijing 2008, was a major international multi-sport event that took place in Beijing, China, from 8 to 24 August 2008. A total of 10,942 athletes from 204 National Olympic Committees (NOCs) competed in 28 sports and 302 events (a total of one event more than the schedule of the 2004 Games). China became the 22nd nation to host the Olympic Games and the 18th to hold a Summer Olympic Games. It was the third time that the Summer Olympic Games were held in East Asia and Asia, after Tokyo, Japan, in 1964 and Seoul, South Korea, in 1988.    Given the information, choose the subject and object entities that have the relation of 'participant of'.
Answer:
cameron winklevoss , 2008 summer olympics