( There ( ( ( is always ) ( ( ( a minimum ) ( of ( two ( weeks difference ) ) ) ) ( in ( lunar ( and ( solar eclipses ) ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBZ is) (ADVP (RB always)) (NP (NP (DT a) (NN minimum)) (PP (IN of) (NP (CD two) (NNS weeks) (NN difference))) (PP (IN in) (NP (NN lunar) (CC and) (JJ solar) (NNS eclipses))))) (. .)))
There is always a minimum of two weeks difference in lunar and solar eclipses.
(ROOT (S (NP (CD Two)) (VP (VBZ is) (NP (NP (DT the) (JJ minimum) (NN number)) (PP (IN of) (NP (NP (NNS times)) (SBAR (S (NP (DT a) (JJ partial) (NN lunar) (NN eclipse)) (VP (MD will) (VP (VB occur) (NP (DT each) (NN year)))))))))) (. .)))