IV. Choose the word (A, B, C or D) that best fits each blank space in the following passage.
Legend (17) ______ it that Isaac Newton formulated gravitational theory in 1665 or 1666 after watching an apple fall and asking why the apple fell straight down, (18) ______ than sideways or even upward. Newton believed the force that made the apple (19) ______ and that held us on the ground was the same as the force that kept the moon and planets in their orbits. (20) ______ gravity was only part of Newton's contribution to mathematics and science. His other major mathematical preoccupation was calculus, and (21) ______ German mathematician Gottfried Leibniz, Newton developed differentiation and integration; techniques that remain fundamental to mathematicians and scientists. In 1727, at 84, Sir Isaac Newton died in his sleep and (22) ______ with pomp and ceremony in Westminster Abbey in London.
