Fill in the blank.
Gas carbon is used as ________ in dry cells.

Explanation

**Step-by-Step Solution:**

1. **Identify the context of the question**: The question asks about the use of carbon in dry cells, which are commonly used batteries.

2. **Understand the role of carbon in dry cells**: In dry cells, carbon is utilized for its properties. It is important to know what function carbon serves in this context.

3. **Determine the correct term**: The term that fits in the blank is related to the function of carbon in the dry cell. Carbon is used as an electrode in these cells.

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