In groups of three, public security officers make each test paper is scanned and uploaded correctly. [Photo/jstv.com]

The visitors were first attracted by the careful and precise paper sorting and scanning procedures.

Many of the papers will be marked digitally, so officials demonstrated how the public security officers, in groups of three, make sure each paper is scanned and uploaded correctly, sent safely to the test markers, then sealed to protect the basic information of every examinee.