Compulsory 3 and compulsory 4. Huizhou Senior One completed the compulsory function in mathematics last semester, and will study compulsory 3 and compulsory 4 next semester. Huizhou refers to Huizhou, also known as Goose City, a prefecture-level city under the jurisdiction of Guangdong Province, one of the central cities in the Pearl River Delta approved by the State Council, and a national historical and cultural city. It is located on the east coast of Guangdong-Hong Kong-Macao Greater Bay Area, with Luofu Mountain as its back and Daya Bay as its south.