Children from china’s many different ethnic groups are taught to read and write in both english and chinese the dialect they speak at home the main dialect of their region mandarin, the northern dialect

Children from China's many different ethnic groups are thought to read and write in both English and Chinese.
Doesn't matter the ethnic group, in China all kids are obligated to learn Chinese (the Mandarin dialect) and English, languages like Japanese are optional, while the local and regional languages like Cantonese, Mongolian, Uighur, are learned at home.

Ithink its d.stratum