Expand the following abbreviations :
HIV

Explanation

**Step-by-Step Solution:**

1. **Identify the abbreviation:** The abbreviation we need to expand is "HIV."

2. **Recall the full form:** The full form of HIV is "Human Immunodeficiency Virus."

3. **Understand the context:** HIV is known as the causative agent of AIDS, which stands for "Acquired Immunodeficiency Syndrome."

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