In this Friday, July 15, 2016 photo, a Chinese couple wearing masks to protect against air pollution walk past a Chinese government propaganda slogan for the “Chinese Dream” in Beijing. Beijing's notoriously awful air quality improved significantly in the first half of the year, with actions taken to curb the city's heavy pollution having a positive effect, officials in the Chinese capital said Monday, July 19, 2016. (Photo by Ng Han Guan/AP Photo)
