How is humic acid present in soil neutralised in earthworm stomach?

Explanation

**Step-by-Step Solution:**

1. **Understanding Earthworm Habitat and Diet**: Earthworms are members of the phylum Annelida and primarily inhabit soil. Their diet consists mainly of decaying organic matter, such as leaves, which they consume along with the soil.

2. **Identifying Humic Acid**: The organic matter in the soil contains humic acid, which is a component of humus. Humic acid is acidic in nature and can affect the pH balance in the earthworm's digestive system.

3. **Role of the Earthworm's Stomach**: When earthworms ingest soil and organic matter, they also take in humic acid. The earthworm's stomach plays a crucial role in processing this material.

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