chlorinated

"The chlorine in the swimming pool keeps it clean. "

"Wear a hat to protect your skin from harmful sunlight."

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

"The prospector claimed his newly discovered land was auriferous, promising riches to his family. "

"She used a water filter to purify the river water before drinking it. "

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

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

"The extract from the textbook was the most important part for the history test. "

"supply and demand"

"The doctor identified the specific bacteria causing the student's illness. "

"I brush my teeth regularly to prevent them from turning yellow."

"My favorite weekend activity is swimming. "