The total number of exhaustible sources among the following is ________ .
Sunlight air, petroleum, coal, natural gas, wind, minerals,forests.

Explanation

To determine the total number of exhaustible sources from the given list, we need to identify which of the items can be depleted or exhausted over time. Here’s the step-by-step solution:

1. **Understand the Definition of Exhaustible Resources**:
- Exhaustible resources are those that can be depleted or used up. They are finite and will eventually run out if consumed at a rate faster than they can be replenished.

2. **List the Given Sources**:
- The sources provided in the question are:
- Sunlight
- Air
- Petroleum
- Coal
- Natural Gas
- Wind
- Minerals
- Forests

3. **Evaluate Each Source**:
- **Sunlight**: This is a renewable resource and will not be exhausted.
- **Air**: This is also a renewable resource and will not be exhausted.
- **Petroleum**: This is a fossil fuel and is an exhaustible resource.
- **Coal**: This is another fossil fuel and is an exhaustible resource.
- **Natural Gas**: This is also a fossil fuel and is an exhaustible resource.
- **Wind**: This is a renewable resource and will not be exhausted.
- **Minerals**: These are finite and can be exhausted.
- **Forests**: These can be depleted if not managed sustainably, making them exhaustible.

4. **Count the Exhaustible Sources**:
- From the evaluation, the exhaustible sources are:
- Petroleum
- Coal
- Natural Gas
- Minerals
- Forests
- Total exhaustible sources = 5

5. **Conclusion**:
- The total number of exhaustible sources among the given options is **5**.