Birds have hollow bones due to the fact thay need to be as light as possible for their wings to generate enough lift for them to fly
Answer:
Body systems. Our bodies consist of a number of biological systems that carry out specific functions necessary for everyday living. The job of the circulatory system is to move blood, nutrients, oxygen, carbon dioxide, and hormones, around the body. It consists of the heart, blood, blood vessels,arteries and veins.
Answer:
if your on a mountian it colder
Explanation:
RUBISCO!
Ribulose-1,5-bisphosphate carboxylase/oxygenase
