The admission ticket of the second-level constructor is printed online, so it cannot be stamped, and it is impossible to determine which department to stamp. The admission ticket printed online can take the exam with ID card.

Another reason why the admission ticket of Erjian does not need to be stamped is that the invigilator has a copy of the information on the admission ticket, including the photos of the candidates; The invigilator can also identify the identity of the candidate by the information in his hand and the ID card of the candidate without looking at the admission ticket carried by the candidate.

Therefore, it is meaningless to stamp the admission ticket of Erjian.