The separation of petroleum into different fractions is done by the process of______.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Process**: The question asks about the method used to separate petroleum into different fractions. This process is essential in the petroleum industry to obtain various products like gasoline, kerosene, diesel, etc.

2. **Identifying the Process**: The correct term for the separation of petroleum into different fractions is "fractional distillation."

3. **Explaining Fractional Distillation**: Fractional distillation is a technique that separates a mixture into its individual components based on their boiling points.

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