Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is
a. radiation.
b. a stream of particles.
c. a wave.
d. heat.

B. A stream of particles, or otherwise known as photons, small pieces of light. All of the rest of the options could never make a shadow. 

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;