..................and...............are some of the main sources of water on earth.

Answer

**Step-by-Step Text Solution:**

1. **Identify the Question:** The question asks for the main sources of water on Earth.

2. **Understand the Types of Water:** Water exists in various forms on Earth, including solid (ice), liquid (water), and gas (water vapor). However, we need to focus on the sources of water.

3. **List the Main Sources of Water:**
- **Ground Water:** This is water that is found underground in aquifers and can be accessed through wells.
- **Surface Water:** This includes water found in rivers, lakes, and reservoirs on the Earth's surface.
- **Rain Water:** This is the water that falls from the atmosphere as precipitation and can be collected for various uses.

4. **Conclude the Answer:** The main sources of water on Earth are ground water and surface water.

**Final Answer:** Ground water and surface water are some of the main sources of water on Earth.

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