Answer:
um i dont think they are i think the earth provides them
Explanation:
Well, From what i know... WWR started in September 1, 1939 because Germany invaded Poland and the U.K and France declared on Germany to protect Poland
Answer:
Air pressure is higher at lower altitudes. Air density is higher at lower altitudes. There is more space between air molecules at higher altitudes. There is less oxygen to breathe at the top of a high mountain than there is at sea level.
PLS MARK THE BRAINLIST!! (❁´◡`❁)