Why is my cousins voice squeaky/ sounds like his 10 and his 15

Can someone give me one specific health problem, and explain it. !

Sadie and her mom were at a hardware store to purchase smoke detectors for their new home. sadie's mom was unsure how many units she should purchase. what is the general recommendation? a. one large one for the middle of the house b. every room in the house should have one c. kitchen, garage and laundry room- since those are where most fires happen d. every living area including the hallway by the bedrooms should have a smoke detector.

List 5 common advertising techniques