State three characteristics of the medium required for propagation of sound?

Explanation

To answer the question regarding the characteristics of the medium required for the propagation of sound, we can outline the following steps:

### Step-by-Step Solution:

1. **Elasticity of the Medium**:
- The first characteristic of the medium is that it must be elastic. Elasticity refers to the ability of a material to return to its original shape after being deformed. This property allows sound waves to be transmitted through the medium as the particles of the medium vibrate and transfer energy to adjacent particles.

2. **Inertia of the Medium**:
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