Question

which of the following is not a metric prefix?
milli
hecto
millo
kilo

Explanation:

Metric prefixes are standardized in the International System of Units (SI). "Milli" (10⁻³), "hecto" (10²), and "kilo" (10³) are all recognized SI metric prefixes. "Millo" is not a valid metric prefix.

Answer:

millo