Qing dynasty:

The Qing organization of provinces was based on the fifteen administrative units set up by the Ming dynasty, later made into eighteen provinces by splitting for example, Huguang into Hubei and Hunan provinces. The provincial bureaucracy continued the Yuan and Ming practice of three parallel lines, civil, military, and censorate, or surveillance. Each province was administered by a governor (巡撫, xunfu) and a provincial military commander (提督, tidu). Below the province were prefectures (府, fu) operating under a prefect (知府, zhīfǔ), followed by subprefectures under a subprefect. The lowest unit was the county, overseen by a county magistrate. The eighteen provinces are also known as "China proper". The position of viceroy or governor-general (總督, zongdu) was the highest rank in the provincial administration. There were eight regional viceroys in China proper, each usually took charge of two or three provinces. The Viceroy of Zhili, who was responsible for the area surrounding the capital Beijing, is usually considered as the most honorable and powerful viceroy among the eight.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What were provinces broken up into?
prefectures