Final answer:
When following a truck at night, you should dim your headlights to avoid reflection and glare, which helps in maintaining clear visibility for both you and the truck driver.
Step-by-step explanation:
When following a truck at night, you should always dim your headlights. This is important because bright headlights might reflect off the truck's large mirrors and back into your eyes, impairing your vision. Dimming your headlights will help both you and the truck driver to see better and avoid glare-related safety hazards. It's also essential to maintain a safe following distance and keep your own visibility clear while driving at night.