Which is the best summary of paragraph 3?
a) fossil fuels are dirty and pollute the air and water. most of the world's energy comes from these fuels.
b) the biggest problem of buildings is that they use fuel that is dirty for heating. they need to do something to be more energy efficient.
c) panels that turn energy from the sun into electricity and passive solar heating can stop the burning of fossil fuels which pollute air and water.
d) since fossil fuels are dirty and pollute the air and water, other technologies that pollute less and produce energy have been developed like solar energy and green buildings.

c. barbarians with unexpected intelligence  

ill need more info in order to answer yer ?

it was surely an odd creature that one made up by reading the historians first and the poets afterwards a worm winged like an eagle; the spirit of life and elegance and charm,   in a kitchen chopping up suet. but these creatures, monst'r however entertaining to the imagination, hast no existence in fact. what one might doth to bringeth h'r to life wast to bethink poetically and prosaically at one and the same moment,   thus keeping in toucheth with fact—that the lady is mrs martin, ag'd thirty-six, did dress in blue, wearing a black coxcomb and brown shoeth; but not losing sight of fiction eith'r—that the lady is a vessel in which all s'rts of spirits and f'rces art coursing and flashing p'rpetually. the moment, howev'r, yond one tries this method with the elizabethan mistress, one brancheth of illumination fails; one is did hold up by the scarcity of facts.   one knoweth nothing detailed, nothing p'rfectly true and substantial about h'r.   hist'ry scarcely mentions h'r.   and i did turn to professeth'r trevelyan again to seeth what hist'ry meanteth to that gent.   i hath found by looking at his chapt'r headings yond t meanteth.