TIDES

1. The gravitational pull causes the oceans to _____ in the direction of the moon and makes the oceans rise higher on land.
7. _____ was the first person to give a scientific explanation for the tides.
9. The _____ were the first people to understand that the moons and tides were somehow linked.
11. Ocean tides are the result of the _____ force between the Sun, Moon and Earth.
12. Spring and neap tides occur twice every _____.

2. When it's low tide, the water is at its _____ level.
3. _____ refers to the "rise" and "fall" of the sea level caused by the gravitational pull between Earth and the Moon.
4. Most areas receive _____ high and low tides each day.
5. The "highest of the high" and the "lowest of the low" tides are called ______ tides.
6. _____ tide occurs on the sides of the Earth closest and farthest from the moon.
8. Moderate tides are also called _____ tides.
10. The _____ pulls on the oceans, but it's pull is only 40% as great as the Moon's because of the distance between it and Earth.
13. In the _____ century, people were using tidal power to help turn wheels to grind grain.