Length units: meters, centimeters and millimeters

Unit of weight: t (ton), kg (kg), g (gram), mg (mg),? Gram (microgram)

Unit of volume: kilograms per cubic meter (kg/m3), liters (liters in words) and milliliters (milliliters in words).

Time unit: days, hours, minutes and seconds.

Area units: hm2 (hectare), km2 (square kilometer) and a (mu)

PH value of aqueous solution: pH (lowercase P, uppercase H)

Light intensity: lx (lux) or lux(l is lowercase)