Answer:
air masses
Explanation:
a front forms where two air masses of different temperatures meet each other
Hope that help
Answer:
1.A tissue is a collection of similar cells that work together to perform a specific job.
An organ is a collection of different tissues that work together to perform a specific job. The function of a part of an organism is what it actually does (it's job)
2.The structure of the alveoli as a web of blood vessels surrounding an air sac allows blood cells take in oxygen and bring it into the lungs (organ)
