ostinato

"The scientists repeated the experiment in order to confirm the result."

"The singer's beautiful voice was enhanced by the soft piano accompaniment. "

"The science textbook included a figure showing the different stages of a plant's growth. "

"They played long and hard."

"The sweet melody of the school bell signaled the end of the day. "

"My grandmother's cough syrup is a simple; it's made from just one type of herb. "

"The student's progression from beginner to advanced level took two years of study. "

"I have to focus on my work."

"He is a student of life."

"The scientists repeated the experiment in order to confirm the result."

"Because she had been a dancer for years, she was a practiced performer. "

"The school's annual musical was a huge success, with the students performing catchy songs and energetic dances. "