请帮我翻译这句话！~

Tianjin is one of the co-sponsor cities of Beijing Olympic Games.

天津作为奥运会的一个协办城市。
Tianjin is one of the co-sponsor cities of Olympic Games.

奥运会在北京举行 由于体育场馆有限 部分比赛项目的预赛就会放到天津去比 这样天津就是奥运会的一个协办城市

Tianjin works as an assissant Olympic Games -holding city.

Tianjin works as an assissant Olympic Games -holding city.

Tianjin does a city jointly as one of Olympiad

Tianjin is regarded as an assistant city of the Olympic Games