kilometers
Kilometers.
Metres.
The answer depends on what you wish to measure: its length (or width or height), its mass, it fuel efficiency, it maximum speed, its maximum acceleration, its tightest turning circle, its power output, its drag, etc.
length would be about 1dm, but dms are not used. centimetres would be more mainstream to use
Any measure of length will do, but the most common would be feet or meters.
mode
The most best unit to measure the length of a slice of pizza are inches.
Centimetre.
It depends on what you're measuring it for. You could be testing it for the following measurements: Height (using meters would be the most appropriate). Length (using meters would be the most appropriate, kilometres if long enough) Mass (tonnes would be the most appropriate). Volume (m3 would be the most appropriate). Area (m2 would be the most appropriate). Time taken to cross (depends on the length of the bridge. Minutes and seconds would be appropriate).
inches
By unit of length and distance and conversion ,we can say that the most appropriate unit to measure the length of a finger is cm.
A tenth of a metre.
feet