Final answer:
Books were rare and expensive in the middle ages because of the lack of printing technology, low literacy rates, and government control of book production.
Step-by-step explanation:
In the middle ages, books were rare and expensive due to a combination of factors. One reason was that printing technology had not yet been developed, so all books had to be copied by hand, which was a laborious and time-consuming process. Additionally, literacy rates were low during this time, reducing the demand for books. Lastly, the production of books was often controlled by the government, limiting the supply and making them even more scarce and expensive.