........... cells present in mammalian testes help to nourish the sperms.

Explanation

**Step-by-Step Solution:**

1. **Identify the Context**: The question asks about the cells in mammalian testes that nourish sperm. This indicates a focus on the structure and function of the testes.

2. **Locate the Relevant Structure**: In mammalian testes, sperm are produced in the seminiferous tubules. Understanding where sperm production occurs is crucial to answering the question.

3. **Understand the Process of Sperm Production**: The process of sperm production is known as spermatogenesis. This is important because it highlights the development of sperm and the cells involved in this process.

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