I believe it's the timeless of the message because, it depends on how much you've written. For example, Amanda wrote a 7 paragraph long essay, and took at least 2 1/2 hours to read it. This is an example to prove that no matter how much you've written your time to read cannot always be timeless!!! Hope this helps!!!
When you preview something, you inspect it. Previewing helps you get a glimpse of what's ahead before you read or something, kind of like skimming.
