Identify the substance underlined
The `ul"acid"` that is a dehydrating as well as a drying agent.

Explanation

To identify the substance referred to as "acid" that acts as both a dehydrating agent and a drying agent, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- A **dehydrating agent** is a substance that removes water from another substance.
- A **drying agent** is a substance that absorbs moisture from the air or from other substances.

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