Question When backing a truck, you should: Answers Only use the side mirrors on the driver’s side. Use both side mirrors. Only use the side mirrors on the passenger's side. Explanation Backing a commercial motor vehicle is always dangerous because you cannot see everything behind you. When backing, make frequent checks of the mirrors on both sides of the vehicle. Take a FREE Practice Test Now This questions appears in the following tests: Idaho Knowledge Test Class A , Nevada Knowledge Test Class B , New Mexico Knowledge Test Class B ,