The decision when to use kilometers and when to use meters is sort of arbitrary. But usually you would use kilometers when you expect the distance to be close to a kilometer, or larger than a kilometer. For example, distances between towns or cities are often expressed in kilometers.
Use units of millimeters, meters, or kilometers.
you would use kilometers.
Americans use miles as the traditional measure of distance.
Kilometers
Miles or kilometers
Kilometers are a unit of length, used to measure distance.
You would use a length/distance unit, such as meters or kilometers.
Scientists use Kilometers to measure distance traveled by a car
It depends on who you mean by 'they.' In the United States, we will use miles for measuring distance. In most other parts of the world, particularly in the European, Australian, Asian, and African continents, they will use kilometers to measure distance.
miles or kilometers
Kilometers
Miles or kilometers.