Which power source has been least developed?

wood

wind

biofuel

hydroelectric

On the question, there should be a graph.  On the graph, you'll have various lines colored blue, red, yellow, turquoise, and dark green.  You basically just wanna look for the line that is the lowest, which should be the dark green line.  Which is the wind line.

So simply put, the answer is Wind.

This is also the answer for "Which power source has been least consumed?".  It's basically the same thing, and same answer.

a and b because with the other three, they simplify to something else.

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 ; -;