CDL Practice Tests

Combination Vehicles Test

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Question #1 of 52

Combination Vehicles Test Question Image

Describe what the service line is for.


The service line carries air, which is controlled by the foot brake or the trailer handbrake.

The service line carries air, which is controlled by the foot brake.

The service line carries air, which is controlled by the trailer handbrake.

None of the above.





CDL Practice Test (Home) | General Knowledge Test 1 (Learning)

General Knowledge Test 2 (Learning) | Air Brake Test 1 (Learning) | Air Brake Test 2 (Learning)

Combination Vehicles (Learning) | Hazardous Materials (Learning) | Doubles & Triples (Learning)

Tanker Test (Learning) | School Bus (Learning) | Passenger Vehicle (Learning)

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