The answer will depend on what aspect the 21 units refer to!
one unit is
Square unit
Quantity K is metric for 1000. For units, it can also refer to Kelvin temperature. It can also refer to Kinetic energy.
A unit ratio.
Well, in the metric system, the base unit for distance is the meter. If that is the unit to which you refer, then there are 1000 milimeters in one "unit", or meter.
eurasia
A cylinder can refer to a grain silo or a tiny pellet. A reasonable unit for one will not be reasonable for the other!
What sort of objects does this refer to?
The unit for energy is the joule. That's also the unit for work and for heat - both of which refer to energy transfers.
The acronym EBU is most often used to refer to the European Broadcasting Union. It may also be used to refer to an equivalent billing unit or an electronics bay unit.
18th infantry
In Greek, "gram" (γραμμή) means "line" or "stroke." It can also refer to a unit of measurement equal to one thousandth of a kilogram.
15 units of wheat are given up to get one more unit of steel.
The area of one unit is one unit2. one unit * one unit = one unit2
If you refer to the unit, the international unit for energy is the joule; the symbol is "J".
The unit ratio for quarters (one-fourth of something) is 4:1Since there are 4 quarters to 1 of whatever you want to refer to, that means for a unit of 1 million, there are 4 million quarters.