Generally speaking, there are germs in books more or less. If a book is circulated for more than 3 years, there will be more than 400 kinds of germs such as influenza, streptococcus, Escherichia coli, hepatitis B virus and tuberculosis. However, in some university libraries and children's libraries, there will be special book sterilizers to sterilize books. For example, both Shanghai Library and Liaoning Provincial Library use a Funuo book sterilizer to sterilize books for 30 seconds at a time! Solved a big trouble for readers!