Breathing and the Lungs! Crossword Puzzle

QUESTIONS LIST:

• nitrogen : which is the most present gas in air?
• alveoli : what are at the end of every bronchiole?
• left : which lung is smaller?
• nicotine : what is the addictive and harmful chemical in tobacco products?
• ribs : what bones help protect the lungs?
• respiratory system : what is the system of body parts that allow you to breathe?
• trachea : what is the air pipe called?
• black : what colour do your lungs turn if you have been smoking?
• oxygen : what gas does breathing allow the body to take in?
• diaphragm : what helps the lungs expand and contract?
• inter costal : what is the name of the muscles that expand your ribs?
• heart : what makes one of your lungs smaller?
• diffusion : what is the name of the process where a substance moves from a high concentration of itself to a low one?
• true : true or false, lungs can float in water?
• tar : what substance narrows bronchioles?