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Air Brakes
Combination Vehicles
Doubles and Triples
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CDL Practice Test
General Knowledge
Air Brakes
Combination Vehicles
Doubles and Triples
Tanker Vehicles
Hazardous Materials
Transporting Passengers
CDL Combination Vehicles Practice Test
Question 1 of 3
What function does the service line perform?
A
Carries air controlled by the footbrake or trailer handbrake
B
Distributes air throughout the cab and to each of the trailers
C
Marks the maximum refill point for air tanks
D
Supplies air to the footbrake and trailer handbrake
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