The first emission control applied to automobile engines was called the __________.
A. preventive combustion venturi system
B. positive crankcase ventilation system
C. pollution control ventilation system
D. pollution combustion vertical system
The first emission control applied to automobile engines was called the __________.
A. preventive combustion venturi system
B. positive crankcase ventilation system
C. pollution control ventilation system
D. pollution combustion vertical system