Magmas can have a variety of chemical compositions for which of the following reasons? source rocks undergo varying degrees of partial melting, producing magmas of a different composition than the rock. all of the possible answers are correct. melts may come from different source rocks. two magmas may mix together to form a third of differing composition.

a characteristic is a deep cut in the earth or left over rock aka till.  

for e2020. the answer would be some directions from the mountain range so we can find mt. whitney. to locate which direction is north, you should use a   compass. this would not only find mt. whitney, but also becuase of this long paragraph you would get points because it's not like anyone actually reads your work becuase once they read the first sentence it sounds dumb enough to not read becuase i'm not good at answering this but the answer is compass for your benefit.

for e2020 ; -;