Final answer:
The pull of the moon and earth on each other causes the Earth to be slightly elongated rather than spherical due to differential forces exerted by the Moon's gravity on different parts of the Earth. This elongation is mostly manifested in the oceans, resulting in the twice-daily rising and falling of tides.
Step-by-step explanation:
The pull of the moon and earth on each other causes the Earth to be slightly elongated rather than spherical. This is due to differential forces exerted by the Moon's gravity on different parts of the Earth. The side of Earth nearest the Moon is attracted more strongly, causing a slight stretching of Earth into an elongated shape called a prolate spheroid. The elongation is mostly manifested in the oceans, resulting in the twice-daily rising and falling of tides.