Shanghai is the largest city by population in China.
Surgery of Tony Stark
Doctor Wu and his assistant Wu Jiaqi operated on Stark, with Stark's closest friends Pepper Potts and James Rhodes accompanying him during the process. The surgery was a success, and eliminated the need for the use of the Arc Reactor in Stark's chest.
Escape from HYDRA
The city of Shanghai in China was the intended destination of Raina after spending a while in Vancouver, having fled from the United States due to Daniel Whitehall's threats of killing her if she did not give him the Obelisk.