Reference book containing 5 years of past questions for the 2020-2024 National Pollution Control Manager Examination. - Title: National Pollution Control Manager Examination: Correct Answers and Hints - Author: Water Quality, Type 1 & Type 4 - Target Years: 2020-2024 - Past Questions Included: 5 years of past questions ※I don't think it will hinder your studies, but it has been used, so there are folds, wrinkles, and some minor stains. Please understand that this is a used item. Please refrain from purchasing if you are sensitive to such things. Due to work, it may take some time to respond to questions. Thank you for your understanding.