Milliliters is the metric unit to use for the capacity of a thimble.
millimeters * * * * * No. Millilitres for capacity. Millimetres is for length!
The metric unit is a millilitre. The metric unit is a millilitre. The metric unit is a millilitre. The metric unit is a millilitre.
The unit will be the mililitre (mL).
Capacity isn't a unit it is just a term that means how much a container holds. You can have metric units of capacity, such as Litres and Millilitres.
By capacity, I assume you mean volume. That would be the liter.
Liters would be the metric measurement for volume of liquid.
Liters would be easiest to use.
You would use millimeters for the measure of the capacity of a paper cup.
The metric unit of measure for volume is cubic units. Other metric unit is liter.