Before graduating from university in 2023, Lin Xing had experienced this kind of time travel three times. Judging from these limited three experiences, he believed that the length of time he traveled back to the past should be related to the size of the danger.,At this moment, the classroom was empty except for Lin Xing. He casually chose a seat and sat down, taking out his books from his bag while continuing to think about his plan.,Just as the classroom was in turmoil, a squad of men in combat gear and armed with firearms were running quickly toward the classroom from outside the teaching building not far away.。