MADISON, Wis. (AP) – Gov. Scott Walker and government and business representatives are returning from a trade mission to China.        They visited Beijing, Tianjin, Harbin and Shanghai during the 10-day trip to Wisconsin’s largest export market. Walker met with Chinese provincial governors, representatives from China’s water and wood sectors, and visited Wisconsin businesses operating in China.  Walker said he believes healthy dialogues between U.S. and Chinese governments is key to sustaining a good economic relationship. He says the real work on the trade mission is done before and after the trip.