This is a detailed explanation of the answers and solutions to the national examination questions, spanning all four volumes. - Title: National Examination Question Answers and Explanations - Author: Environmental Measurement Specialist - Publisher: Corona Publishing Co., Ltd. - Volumes: 4 volumes total - Contents: Contains answers and explanations for national examination questions Thank you for viewing. This is a used item, and as shown in the photos, there are considerable markings, scratches, and stains. Please understand this before purchasing.