Write which of the following statements are true? Justify your answer: The set of all real numbers is contained in the set of all complex numbers.

Explanation

To determine whether the statement "The set of all real numbers is contained in the set of all complex numbers" is true, we can analyze the definitions of both sets.

### Step-by-Step Solution:

1. **Define the Sets**:
- The set of all real numbers is denoted by \( \mathbb{R} \).
- The set of all complex numbers is denoted by \( \mathbb{C} \).

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