What is the role of cilia in the respiratory tract?

Explanation

### Step-by-Step Solution:

1. **Understanding Cilia and Their Location**:
- Cilia are tiny hair-like structures that are present on the surface of certain epithelial cells. In the respiratory tract, these cilia are found on the free surface of ciliated pseudostratified columnar epithelium.

2. **Function of Cilia**:
- The primary role of cilia in the respiratory tract is to facilitate the movement of mucus. Mucus is produced in the respiratory tract to trap dust, pathogens, and other particles that enter the airways.

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