Fill In the blanks:
There is practically limitless supply of _____ source of energy.

Explanation

To solve the fill-in-the-blank question, we need to identify the type of energy source that is described as having a practically limitless supply.

### Step-by-Step Solution:

1. **Understand the Context**: The question states that there is a practically limitless supply of a certain type of energy source. This implies that the energy source can be replenished naturally and is not finite.

2. **Identify Types of Energy Sources**: We need to think about different types of energy sources. They can be broadly categorized into renewable and non-renewable sources.

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