Gross `CO_(2)` emission from coal is more than that from _____and about double the amount from _____.b) Every compound of the ecosystem is connected to one another in a______.

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the gross CO2 emissions from coal compared to other fossil fuels. We need to identify which fossil fuel has lower emissions than coal and which one has emissions about double that of coal.

2. **Identifying Fossil Fuels**: Coal is a type of fossil fuel. The other common fossil fuels are natural gas and petroleum.

3. **Comparing CO2 Emissions**:
- **Natural Gas**: It is known that natural gas emits less CO2 compared to coal when burned.
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