I want to know the answer to the following question:
When did a thick wave of smog first appear in Central and Eastern China?
All the background I'm provided with is that "A dense wave of smog began in the Central and Eastern part of China on 2 December 2013 across a distance of around 1,200 kilometres (750 mi), including Tianjin, Hebei, Shandong, Jiangsu, Anhui, Shanghai and Zhejiang.". Is that enough to answer the question?