An ____ is a mixture of minerals in the earth's crust from which it is profitable to extract a metal.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question states, "An ____ is a mixture of minerals in the earth's crust from which it is profitable to extract a metal." We need to fill in the blank with the correct term.

2. **Defining Minerals**: Minerals are natural materials found in the earth's crust that contain metals and their compounds. They are the raw materials from which metals can be derived.

3. **Defining Ores**: Ores are specific types of minerals that contain enough metal to make extraction profitable. They are the minerals from which metals can be extracted conveniently and profitably.

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