Distance is measured in kilometres, such as the distance between two towns, or the distance from the Earth to the Moon.
Distance.
Planets are usually measured in miles or kilometres.
Elevation can be measured in feet and inches, or metres and centimetres.
Correct, the length of a race can be measured in kilometres.
No.
If you mean kilometres, the answer is distance.
Mass is not measured in kilometres.
There are many instances: for example, speed is measured in kilometres per hour where the ratio is measured between a distance (measured in kilometres) and time (measured in hours). So it is no big deal except that you need to mention the units.
Road distance in the United States is measured in miles.
In SI units. Depending on the scale, they are measured in kilometres, metres, centimetres, millimetres etc.
Speed.
Distances to stars are not measured in kilometres, but since you have asked, Polaris is 3-4 quadrillion kilometres away.