secretion

"He is a student of life."

"My friend told me there was something in the box, but I didn't know what it was yet. "

"The single-celled organism was studied by the biology students in their science class. "

"The scientist carefully examined the substance to determine its chemical composition. "

"My sister is very helpful, especially when it comes to organizing things. "

"The shy student secreted the note under his desk, hoping no one would see it. "

"The weather forecast for today predicts rain and strong winds, so I should bring an umbrella to school. "

"He listened carefully to his mother's concerns, feeling sorrowful about her disappointment. "

"Check the oil in your car once a month."

"She was secreting notes to her friend during class, hoping the teacher wouldn't notice. "

"the performance of an undertaking or a duty"

"The teacher pointed to the student's forehead and said, "Concentrate!" "