Let's analyze each sentence for corrections needed:

1. **Sentence**: Noise pollution can have a negative effect **in** both human health and wildlife.
- **Correction Needed**: C. in (should be "on")
- **Revised Sentence**: Noise pollution can have a negative effect **on** both human health and wildlife.

2. **Sentence**: If you don't pay attention, you **will understand** the lesson.
- **Correction Needed**: B. will (should be "won't")
- **Revised Sentence**: If you don't pay attention, you **won't understand** the lesson.

3. **Sentence**: It **is** too hot today - please turn **on** the air **condition**.
- **Correction Needed**: D. condition (should be "conditioning")
- **Revised Sentence**: It is too hot today - please turn on the air **conditioning**.

To summarize:
1. C. in → should be "on"
2. B. will → should be "won't"
3. D. condition → should be "conditioning"