| A | B |
|---|
| gravity | The force that pulls fresh water toward the ocean |
| currents | Streams of water moving like rivers through the ocean |
| waves | The up and down movements on the surface of the ocean |
| wind | The cause of most waves and surface currents |
| tides | regular changes in the water level of the ocean |
| three-fourths | Amount of earth covered by water |
| salt and fresh | two kinds of water on earth |
| fresh water | carries minerals and nutrients to the ocean |
| plankton | tiny plants and animals that live on or near the surface of the ocean |
| surface currents | these afect the climate of land that they are near |
| water cycle | The path water takes as it travels between the earth and the air |
| tides | Caused by the gravitational pulls of the sun and the moon on the ocean |
| waves | Underwater earthquakes, volcanoes, and landslides sometimes cause these |
| Pacific Ocean | The largest and deepest ocean |
| Atctic Ocean | The smallest and shallowest ocean |
| Deep ocean currents | This controls the temperature changes and the amount of salt in the water |
| tides in different places | This happens because the earth is rotating as the moon pulls on the water. |
| Size of waves | This is determined by the wind's speed, the distance the wind blows, and by how long the wind blows. |
