Here are the words to complete the sentences:
- "water that is locked in glaciers, polar ice caps, and permafrost melts. This produces fresh water, which fills the oceans, rivers, and lakes of the world. This water then evaporates, becoming water vapor, which condenses into clouds and returns to the Earth’s surface as precipitation."
So the complete sentences would read: "Important changes in the hydrosphere occur via the water cycle, in which water that is locked in glaciers, polar ice caps, and permafrost melts. This produces fresh water, which fills the oceans, rivers, and lakes of the world. This water then evaporates, becoming water vapor, which condenses into clouds and returns to the Earth’s surface as precipitation."