Book Game from Facebook

This one is quite fun to do. Post it here in the comments section or at your own blog.

Rules:
* Grab the book nearest you. Right now.
* Turn to page 57.
* Find the fifth sentence.
* Post that sentence along with these instructions in a note to your wall, and post your sentence in a comment here as well. Include the title of book and author.

My book:

"Pressure is one of the most fundamental and important variables in aerodynamics, as we will soon see."

Introduction to Flight by John D. Anderson, Jr.