Liquid `"___________"` is used for preserving biological specimen

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a specific liquid that is used for preserving biological specimens. This indicates that we need to identify a liquid that has properties suitable for preservation.

2. **Identifying the Purpose of Preservation**: The preservation of biological specimens typically requires conditions that prevent decay or degradation. This often involves maintaining low temperatures to slow down biological processes.

3. **Recognizing Suitable Liquids**: One of the most effective methods for preserving biological specimens is through the use of cryogenic liquids. These are substances that exist in a liquid state at very low temperatures.

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