Why food does not enter the respiratory tract when there is a common cavity for both food and air?

Explanation

### Step-by-Step Solution:

1. **Understanding the Common Cavity**:
- In humans, both the respiratory and digestive systems share a common passage known as the pharynx. This is where the air and food initially meet.

2. **Identifying the Pathways**:
- The air enters the respiratory tract through an opening called the glottis, which is located at the top of the trachea. The food, on the other hand, travels down the esophagus.

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