In an……………………Organ pipe, both odd and even harmonics are present.

Explanation

To answer the question, "In an organ pipe, both odd and even harmonics are present," we need to identify the type of organ pipe that allows for both harmonics. The correct answer is:

**Open Organ Pipe**

### Step-by-Step Explanation:

1. **Understanding Organ Pipes**: Organ pipes can be classified into two types: open and closed. An open organ pipe is open at both ends, while a closed organ pipe is closed at one end and open at the other.

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