Practice question

The trailer hand valve should:

  1. Be used for parking.
  2. Be used only to test the trailer brakes.
  3. Be used together with the brake pedal.
  4. Be used on slippery surfaces.

Answer: B — Be used only to test the trailer brakes.

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: District Of Columbia CDL Combination Test 2 →