All the boats operating at night requires Navigation light.
Navigation light helps prevent collisions between boats and see if visibility is poor. The types of boat are : Rowboats, Tug boats, Vessels, Sailboat etc.
Various boats have different lightning color to show its use and side of the boat.
Answer: Smoking cigarettes
Explanation: The other options don't cause pollution to form in the air besides smoking, from the particles it creates causing harm and damage to your lungs and fill the air with smoke particles.
Average speed = (total distance covered) / (time to cover the distance)
Total distance covered = (9.5m + 3.5m + 15m) = 28 meters
Time to cover the distance = 43 seconds
Average speed = (28 meters) / (43 seconds)
Average speed = 0.65 meters/second
