Why cant you see a book in the dark room?

Answer 1

Because in order to see you need light. You need light because light reflects off things and bounces back to your eyes, and that's how you see things. So if there isn't any light in a dark room then light can't bounce back and you can't see the words

Answer 2

You can't see a book in a dark room because there is not enough light to reflect off the pages and into your eyes, which are needed for you to see the book clearly. Without enough light, the details of the book will not be visible to you.