What do you mean by marble cancer?

Explanation

**Step-by-Step Solution:**

1. **Definition of Marble Cancer**: Marble cancer refers to the corrosion or deterioration of marble structures, such as buildings and statues. This term is used to describe the damage that occurs to marble surfaces over time.

2. **Causes of Marble Cancer**: The primary cause of marble cancer is exposure to acid rain. Acid rain is precipitation that has been made acidic by pollutants in the atmosphere.

3. **Composition of Acid Rain**: Acid rain contains harmful components, primarily sulfuric acid and nitric acid. These acids are formed when sulfur dioxide and nitrogen oxides are released into the atmosphere, often from industrial processes and vehicle emissions.

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