Give the names of two main parts comprising nervous system of earthworms?

Explanation

### Step-by-Step Solution:

1. **Identify the Organism**: The question pertains to the nervous system of the earthworm, which belongs to the phylum Annelida.

2. **Recognize the Nervous System Structure**: The nervous system of the earthworm is primarily composed of two main parts.

3. **Name the First Part**: The first part of the nervous system is the **nerve ring** (also known as the nerve collar). This structure encircles the pharynx of the earthworm and is formed by a collection of ganglia.

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