About the Author William D. Callister is currently an adjunct professor in the Department of Engineering at the University of Utah. His teaching interests include writing and revising introductory materials science and engineering textbooks, in both print and electronic formats. He also enjoys developing ancillary resources, including instructional software and on-line testing/evaluation tools. Read more
Posted by Anastasia J G
wtffff i do not understand this!
Posted by Cristian
so many fake sites. this is the first one which worked! Many thanks
Posted by John Macciva
lol it did not even take me 5 minutes at all! XD