The speed of light in a vacuum is approximately 2.99 × 108 m/s, and the speed of light through a piece of glass is approximately 1.97 × 108 m/s.

Iwannasay c is the most accurate

Answerthe global climate during the paleogene departed from the hot and humid conditions of the late mesozoic era and began a cooling and drying trend which dispite having been periodically disrupted by warm periods such as the paleocene-eocene thermal maximum, persists today;