BEIJING, June 18 -- President Xi Jinping focused on food safety, big data and vocational development during his visit to southwest China's Guizhou Province that ended Thursday.

During his trip, Xi visited a small supermarket at a highway service area on his way from the city of Zunyi to Guiyang, the provincial capital.

Picking up a package of snacks, Xi asked a member of the supermarket staff about its expiration date and was told it would expire at the end of this year.

Xi also inspected two street-side food stands which sold stewed duck necks and other local foods. In China, substandard foods have been a safety concern in recent years.

In Guiyang, the president visited a big data research center where more than 400 enterprises gathered to develop the technology. Xi talked to the heads of companies engaging in building Internet hospitals and affirmed their plans of offering high-end, online health services, which will gather 1,000 top doctors.

Xi was also shown a miniature 3D-printed drone built by a laser technology company and was told about big data usage in disaster relief operations.

As the country's first big data exchange, the center in Guiyang could trade 30 kinds of data. Xi said it was "reasonable" for Guizhou to develop big data.

Guizhou is home to data centers for China Mobile, China Unicom and China Telecom, the three largest Chinese telecommunication operators. Xi visited China Telecom's cloud computing research park and watched demonstrations of its Internet applications.

In China Telecom's data centers, each room housed nearly 2,000 servers. Xi was told the fourth-generation data centers were completely developed independently and there would be more than 800,000 servers after the construction of the state research park finished.

Although Guizhou is among the least developed regions in China, it has put more efforts developing its big data industry since last year, establishing a state-level big data agglomeration and aiming to contain two million servers. Some cities in Guizhou offer free city-wide WiFi service .

At a vocational school in Guiyang, Xi talked to a student learning to operate mechanical arms used manufacturing. Xi was then given an aluminum flake inscribed with the school motto, which was printed by a 3D printer.