Why does ice melt slowly at higher altitudes?

Explanation

### Step-by-Step Solution:

1. **Understanding the Conditions at Higher Altitudes**:
- At higher altitudes, both temperature and pressure are generally lower than at sea level. This is an important factor in understanding the melting of ice.

2. **Phase Equilibrium of Ice and Water**:
- Ice and water can exist in equilibrium at a certain temperature. For ice to melt and convert into water, heat energy must be supplied to the system.

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