A guide analyzing the problems of the past 30 years and explaining the questions with a high probability of appearing on the Class 4 Hazardous Materials examination. - Title: Past Question Analysis! Class 4 Hazardous Materials Examination Solution Guide - Author: Takao Suzuki - Contents: Includes questions with a high probability of appearing from the past 30 years of problems - Purpose: Preparation for the Class 4 Hazardous Materials examination Thank you for viewing.