a centimeter
Probably the most suitable unit of measurement.
In the US, I would use yards.
A millinewton. NOT a gram, which a measure of mass, not of weight.
Kilometers
square footage
You would use the metric unit of millimeters (mm) to measure the size of a common house fly.
We use grams (g) as the unit of measurement to measure mass on a triple beam balance.
Feet.
a centimeter
A shoe.
You would use CM or INCHES to measure a knife
You could measure the length of a lunchroom in feet or meters, depending on which unit of measurement you prefer to use.
A kilometre.
Kilometers
Decibell
feet