Postgraduate entrance examination can be handed in in advance. You can hand in your papers 30 minutes before the end of the exam, but candidates are not allowed to continue the exam after handing in their papers, and they are not allowed to stay or talk in the area designated by the examination institution. So you need to hand in your papers carefully in advance and check them carefully after you finish.

/kloc-after 0/5 minutes, late candidates are not allowed to enter the examination room to take the local exam, and the time for handing in papers should not be earlier than 30 minutes before the end of the local exam. The specific appearance time shall be stipulated by the provincial education entrance examination institutions. Candidates are not allowed to re-enter the examination room after handing in their papers, nor are they allowed to stay or talk in the area designated by the examination institution. Candidates can't start answering questions until the test signal is issued.