Why can't you see the blue sky in Liuzhou?

Liuzhou city (especially around Liugang) is mainly an industrial city, as the landlord said. Although the geographical location of Liugang is not very good, due to the influence of Siberian cold wind, northwest wind blows in winter, so some steelmaking dust will be blown to the urban area. Because of industrial inertia, the cost of moving Liugang is too high ... but after rainy days, especially heavy rains (beautiful blue sky will be seen in urban areas), if it is a county in Liuzhou, it can be seen all year round.