The author may agree that to call time on the human race by necessity would be ______.

A．Leaving the timing to nature.
B．The saurian-like elimination.
C．Being burned by the sun's heat.
D．An exit driven by man's rationality.

A．Newton was motivated to write the Principia after he saw the apple fell.
B．The Law of Universal Gravitation was originally included in the Principia.
C．Newton began to form the idea of the Principia when he was a college student.
D．The Law of Universal Gravitation was formulated long before the Principia.