Question

Kepler's work revealed that the Earth was _____.

Answer 1

Kepler's work revealed that the orbit of each planet is an ellipse,
with the sun at one focus.

Answer 2

Kepler's work revealed that the orbit of each planet is an ellipse,
with the sun at one focus.

Newton's work revealed that if his law of universal gravitation is
correct, then the orbit of each planet must be an ellipse with the
sun at one focus.