Practice question

Air tank drains:

  1. Allow rain water to enter an air tank.
  2. Are used to drain water and oil from an air tank.
  3. Should never be opened.
  4. Must remain open during driving.

Answer: B — Are used to drain water and oil from an air tank.

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

Practice more: Massachusetts CDL Class B Knowledge Test 2 →