that crawls along at a snail 's pace 
(ROOT (S (NP (DT that)) (VP (VBZ crawls) (ADVP (RB along)) (PP (IN at) (NP (NP (DT a) (NN snail) (POS 's)) (NN pace))))))
(ROOT (S (NP (DT )) (VP (VBZ ) (ADVP (RB )) (PP (IN ) (NP (NP (DT ) (NN ) (POS )) (NN ))))))