How many pairs of tubular hearts are present in the earthworm ?

Explanation

To answer the question "How many pairs of tubular hearts are present in the earthworm?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Tubular Hearts**:
- Tubular hearts are tube-like structures that function as a part of the circulatory system in earthworms.

2. **Identifying the Number of Pairs**:
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