Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. v Illustrations updated for this edition have been designed to clearly and simply communicate the specific topic. Things to Do prompt students to continue learning about arc welding outside of the classroom, encouraging self-directed learning that will benefit them throughout their careers. Check Your Progress review questions are provided in multiple formats for well-rounded testing of student comprehension and high retention of information and concepts.