Question Before starting down a hill, be sure to: Answers Accelerate. Switch into a high gear. Sound your horn. Switch into a low gear. Explanation Before starting down a hill, be sure to switch into a low gear. Gravity will increase your vehicle's speed as you travel downhill. Take a FREE Practice Test Now This questions appears in the following tests: Kansas Knowledge Test Class B , Mississippi Bus , Florida Air Brakes , North Carolina Air Brakes , Pennsylvania Air Brakes , South Dakota Air Brakes ,