abrasive

"What irritation causes you to be so moody?"

"I heard a small fragment of the conversation."

"Dust particles floated in the sunbeam coming through the window. "

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

"The president has a unique personality."

"The students collaborated on their science project to earn a good grade. "

"The magician was revealing his trick by showing how the disappearing box worked. "

"The scouts reported on the disposition of the enemy troops."

"He polished up the chrome until it gleamed."

"She was smoothing the wrinkles out of her dress before the meeting. "

"The heavy box underlying the lighter one caused the whole stack to wobble. "

"Before painting the walls, she used sandpaper to smooth out the rough spots. "