Complete each of the following sentences by choosing the correct term from the word bank.
loudness, echoes, pitch, noise, solids, sound quality, vibrations, wavelength frequency, wave, vacuum, amplitude, lesser, infrasonics, ultrasonics
When a body vibrates, the number or-crests and troughs made in one second is called __________.

Explanation

To complete the sentence, we need to identify the correct term that fits in the context provided. The sentence is:

"When a body vibrates, the number of crests and troughs made in one second is called __________."

### Step-by-Step Solution:

1. **Understanding the Terms**: We need to focus on the terms related to wave motion. The terms in the word bank include 'frequency', 'wavelength', 'amplitude', etc.

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