______ and ______ are two types of underground water.

Explanation

**Step-by-Step Solution:**

1. **Understanding Underground Water**:
- Underground water refers to water that is found below the water table. It is an essential part of the water cycle and is crucial for various uses such as drinking, irrigation, and industrial processes.

2. **Identifying Types of Underground Water**:
- There are two main types of underground water that we will focus on: well water and spring water.

3. **Defining Well Water**:
- Well water is obtained from a well, which is a structure created by digging or drilling into the ground to access water that is below the water table. This water is often used for domestic and agricultural purposes.

4. **Defining Spring Water**:
- Spring water is water that naturally flows from an underground aquifer to the surface. This occurs when the pressure in the aquifer forces the water out, creating a spring. Spring water is often collected for drinking and other uses.

5. **Final Answer**:
- The two types of underground water are **well water** and **spring water**.

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