Meters for height
Kilograms for mass.
Weight and/or height
You would not. A fraction is a pure number - with no measurement units associated with it. A weight is a measure of force.
It depends on what characteristic you want to measure! Its mass, its height, the amount of body fat, the fineness of its fleece?
In the metric system, the units of measurement of Volume is the Liter (sometimes spelled Litre) and the measurement for mass would be the gram. In the American system, the units of measurement for Volume is the ounce, and for mass would be the pound.
No. You would use different units of measurement. You would measure the size (circumference) of your waist (for trousers) in centimetres. You would not measure the distance to the moon in centimetres!
Feet.
Weight and/or height
Yes height could be measured in these units. These units describes length.
Cubic units
Units aren't used to measure anything. After you complete the measurement, using equipment suited to the purpose, you use units to describe the result of your measurement, and to tell other people about it. I would measure the thickness of a hair using a micrometer, and express the result in millimeters.
What metric unit would you use to measure a computer keyboard
The same units that you use for length and distance. For example, the SI unit would be the meter.
A ruler would work best if you are wanting to measure the length of an eye dropper.
You would not. A fraction is a pure number - with no measurement units associated with it. A weight is a measure of force.
Volume is measure as width times height by depth no matter the system you're using. The metric system would just define the type of measurement you would use, such as liters instead of gallons.
In SI units, use centimeters or meters. In non-SI units, use inches or feet.
I would use meters.