( ( ( The ( ultimate source ) ) ( of ( energy ( for ( these transfers ) ) ) ) ) ( ( is ( ( ( the sun ) , ) ( ( whose energy ) ( can ( be ( used ( both ( ( directly and ) indirectly ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ ultimate) (NN source)) (PP (IN of) (NP (NP (NN energy)) (PP (IN for) (NP (DT these) (NNS transfers)))))) (VP (VBZ is) (NP (NP (DT the) (NN sun)) (, ,) (SBAR (WHNP (WP$ whose) (NN energy)) (S (VP (MD can) (VP (VB be) (VP (VBN used) (ADVP (CC both) (RB directly) (CC and) (RB indirectly))))))))) (. .)))
The ultimate source of energy for these transfers is the sun, whose energy can be used both directly and indirectly.
(ROOT (S (NP (NP (JJS Most)) (PP (IN of) (NP (NP (DT the) (NN energy)) (VP (VBN used) (PP (IN by) (NP (VBG living) (NNS things))))))) (VP (VBZ comes) (ADVP (CC either) (RB directly) (CC or) (RB indirectly)) (PP (IN from) (NP (DT the) (NN sun)))) (. .)))
Most of the energy used by living things comes either directly or indirectly from the sun.