( ( The Sun ) ( ( ( ( transfers heat ) ( to ( the Earth ) ) ) ( through radiation ) ) . ) )
(ROOT (S (NP (DT The) (NNP Sun)) (VP (VBZ transfers) (NP (NN heat)) (PP (TO to) (NP (DT the) (NN Earth))) (PP (IN through) (NP (NN radiation)))) (. .)))
The Sun transfers heat to the Earth through radiation.
(ROOT (S (NP (NP (NNP Heat) (NN energy)) (PP (IN from) (NP (DT the) (NN sun)))) (VP (VBZ is) (VP (VBN transferred) (PP (TO to) (NP (NN earth))) (PP (ADVP (RB primarily)) (IN by) (NP (NN radiation))))) (. .)))
Heat energy from the sun is transferred to earth primarily by radiation.