Why do many ethnic groups in Gansu use Chinese as a second language?

In Gansu, Han Chinese constitute the majority of the population, and their language serves as the primary medium for communication across the province. Because of the widespread presence of the Han and the integration of various ethnic groups within the broader Chinese state, many minority groups—including Tibetans—have adopted Chinese as a second language to facilitate communication and interaction with other groups.12

While these minority groups maintain their own distinct cultural and linguistic traditions, the influence of the Han majority and the development of infrastructure, such as highways, have increased opportunities for inter-ethnic communication. Furthermore, the government has established educational facilities and promoted literacy, which has contributed to the use of Chinese as a common language. Notably, while most ethnic groups in the region use Chinese as a second language, the Monguors are a significant exception, as they rarely speak a second language.231