
At high altitudes, there is less oxygen. Oxygen is a gas in the air. Our bodies need oxygen to survive. When we do not have enough oxygen, we get sick.
Photo Credit: Adam Sternin/Cavan Images/Image Source
This is Arenal Volcano in Costa Rica. Look at the … read more
Raindrops are like prisms. When light goes through a prism, … read more
Mammals use moisture to cool off when they are hot. … read more
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