IV. Choose the word (A, B, C or D) that best fits each blank space in the following passage.
Earth's Moon is the brightest and largest object (17) _________ our night sky. The Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate. It also causes tides, (18) _________ a rhythm that has guided humans for thousands of years. The Moon was likely formed after a Mars-sized body collided with Earth several billion years ago. Earth's only natural satellite (19) _________ "the Moon" because people didn't know other moons existed until Galileo Galilei discovered four moons orbiting Jupiter in 1610. In Latin, the Moon was called Luna, (20) _________ is the main adjective for all things Moon-related: lunar. (21) _________ Earth, the Moon has a day side and a night side, which change as the Moon rotates. The Sun always illuminates half of the Moon while the other half remains (22) _________.
