AFP: China’s capital Beijing on Thursday shared the title of most polluted city in the country, as delegates from around the world worked in nearby Tianjin towards a deal to combat global warming. The China Environmental Monitoring Centre rated both Beijing and the central city of Zhengzhou as having "slightly polluted" air — a rating of III2 on scale from I (excellent) to V (hazardous). The US embassy in Beijing, however, qualified the air as "hazardous" in its own measurements …