Either cyan bacteria or Precambrian time<span />
The cliff is 319. kilograms above the water
The units for mass are grams (g) and kilograms (kg)
the units for volume are millilitres (ml) and litres (l)
The speed of light in vacuum is exactly
299,792,458 meters per second.
That's so exact that it's the official scientific definition of a "meter".
The number doesn't t change even if the flashlight or other light source is moving.