undulation

"My brother is a talented guitarist. "

"The phone on the table was vibrating, signaling an incoming call. "

"His sudden appearance surprised me."

"From this vantage point we can observe the behavior of the animals in their natural habitat."

"The hypnotist mesmerized the student, calming her anxiety before the presentation. "

"Her voice was tremulous as she announced she had won the scholarship. "

"Her distinctive laugh, a high-pitched giggle, could be heard across the entire playground. "

"The heavy rain was unexpected; we had planned a picnic in the park. "

"heat radiation"

"The cell phone emits electromagnetic waves that allow us to communicate. "

"Hey, beautiful!"

"The breeze was gently undulating the tall grass in the field. "