I choose humans as friends, though not all humans can be good friends. I think only humans are able to understand human, while the book is an object, highly dependent ability of our knowledge to understand it. A friend is always there for us, where we discuss and complain. The book may have a lot of knowledge in it, but he has no feelings and is unable to teach us about feelings. Therefore, I still choose human as a friend.
In my opinion, humans not only need knowledge or other information, but humans also have a desire to be heard by others. Humans need attention, humans need to be respected and heard. All that can not be given by a book. The book for me is just a tool for exploring various knowledge and information.