C22 Questioning

"Dean, Miss Yang was poisoned with arsenic trioxide." As Lin Feng said this, his eyes kept staring at Li Yun.

"What, arsenic trioxide?" The faces of everyone present changed. Perhaps this name was unfamiliar to them, but it had another name, arsenic.

Perhaps in ancient times, it was just a poison, but it still had miraculous effects in various fields of medicine. For example