
When people climb tall mountains, they bring oxygen. They carry it in tanks. It helps them breathe. It helps them reach the top!
What Do You Think? Would you try mountain climbing? Why or why not?
Photo Credit: Rapt.Tv/Alamy Stock Photo
Chemists study matter and how it changes. They make new … read more
Reptiles are born on land. They have lungs only. They … read more
Animals get cold in the winter, too. Some birds fly … read more
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