Mirrors should be used: Question Mirrors should be used: Answers Only when there may be an emergency. Regularly. By a helper to monitor your blind spots. Explanation When driving, you should frequently check the mirrors on both sides of your vehicle. This questions appears in the following tests: Alaska Double Connecticut Class A Knowledge Test Iowa Tank Missouri Double Nevada Class A Knowledge Test New Mexico Class A Knowledge Test Oklahoma Tank Oregon Class A Knowledge Test South Carolina Class B Knowledge Test South Dakota Tank