In the lungs, the bronchi divide into…

• Bronchioles
• Alveoli
• Lungs
• Bronchitis

Where is oxygen transferred to the bloodstream?

• In the alveoli
• In the diaphragm
• In the intestines
• In the bronchis

What gas is used to extract energy from nutrients?

• Oxygen
• Carbon dioxide
• Nitrogen
• All of them
• None of them

Part of the circulatory system made up of cells, water and dissolved substances

• Blood
• Blood vessels
• Heart

Blood vessels that take the blood from the heart to the organs

• Arteries
• Veins
• Capillaries
• All of them

What kind of blood have bright red color?

• Oxygen-rich blood
• Carbon dioxide-rich blood
• Arteries blood
• Veins blood

When you breathe, your lungs take in ___ and remove ___. 

• air/oxygen
• oxygen/carbon dioxide 
• carbon dioxide/waste 
• waste/air 

Which does not make up the circulatory system?

• heart
• blood
• lungs
• blood vessels

The heart pumps blood to get ________ to our cells.

• carbon dioxide
• urea
• oxygen

What is the main organ in the circulatory system?

• vein
• lung
• heart
• aorta