1. BEIJING - Grey haze was reported over a vast portion of Central China on Tuesday, and is believed to have been caused by farmers burning straw.
2. An image taken on the surface shows chunks of what scientists say looks like water ice scattered over an orange surface overcast by methane haze.
3. Some media agencies have projected the haze over Beijing as smog, and deliberately used it as a sign of the high pollution level in the city.
4. Over the weekend, heavy smog and haze enveloped Beijing and other parts of North China.