Fill in the following blanks with suitable words:
In earthworm, exchange of gases occurs through the ……………

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: The question refers to the earthworm, which is a type of annelid.

2. **Understand the Process of Respiration**: In earthworms, respiration involves the exchange of gases, specifically oxygen and carbon dioxide.

3. **Determine the Site of Gas Exchange**: Unlike many organisms that have specialized organs for respiration (like lungs in humans or gills in fish), earthworms rely on their skin for gas exchange.

4. **Consider the Condition of the Skin**: For effective gas exchange, the skin of the earthworm must be moist. This moisture allows oxygen to dissolve and diffuse into the body while carbon dioxide can diffuse out.

5. **Conclude with the Correct Term**: Therefore, the blank in the statement can be filled with "moist skin".

**Final Answer**: In earthworm, exchange of gases occurs through the **moist skin**.

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