to probe questions of attraction and interdependence 
(ROOT (S (VP (TO to) (VP (VB probe) (NP (NP (NNS questions)) (PP (IN of) (NP (NN attraction) (CC and) (NN interdependence))))))))
(ROOT (S (VP (TO ) (VP (VB ) (NP (NP (NNS )) (PP (IN ) (NP (NN ) (CC ) (NN ))))))))