When an oil well is drilled through rocks, ______ comes out first.

Options

A. marsh gas
B. coal gas
C. natural gas
D. gas carbon

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks what comes out first when an oil well is drilled through rocks.

2. **Identifying Components of an Oil Well**: An oil well typically contains both petroleum and natural gas.

3. **Drilling Process**: When an oil well is drilled, the drilling process allows for the release of gases and liquids trapped in the rock formations.

4. **Order of Release**: According to the information provided, when the drilling occurs, natural gas is released before petroleum.

5. **Conclusion**: Therefore, when an oil well is drilled through rocks, the first substance that comes out is **natural gas**.

**Final Answer**: Natural gas comes out first when an oil well is drilled through rocks.

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