Question Blocking is used to: Answers Keep cargo in a large box. Prevent cargo from sliding in a trailer. Prevent cargo from falling out of a trailer. Explanation Blocking may be used on all sides of a piece of cargo to keep it from sliding while the vehicle is in motion. This questions appears in the following tests: Alaska Class A Knowledge Test Arizona Class B Knowledge Test Connecticut Class A Knowledge Test Idaho Class B Knowledge Test Iowa Class B Knowledge Test Kentucky Class A Knowledge Test Montana Class A Knowledge Test New Mexico Class B Knowledge Test Oklahoma Class B Knowledge Test Oklahoma Class B Knowledge Test Rhode Island Class A Knowledge Test South Carolina Class B Knowledge Test