An academic master with complete knowledge of modern physics and chemistry has traveled to an era of "imperial examination only" where he was least good at these things. She couldn't change the thinking of ancient people, so she chose to change the world. She used scientific theories as a "golden finger". While taking part in the imperial examination to gain secular status, she also made inventions and creations as amulets. Her logic is: If you don't cause trouble during time travel, it's better to go home and plant sweet potatoes.
