What bad effects does tobacco have on respiratory system? Name two toxic substances present in it.

Explanation

### Step-by-Step Solution:

1. **Understanding Tobacco and Its Effects**:
- Tobacco, particularly in the form of tobacco smoke, has numerous adverse effects on the body, especially the respiratory system. It is important to focus on how it impacts the respiratory system specifically.

2. **Irritation of the Airway**:
- Tobacco smoke irritates the trachea (windpipe) and larynx (voice box). This irritation can lead to discomfort and various respiratory issues.

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