(S (S (BASENP (NN These)) (VP (VBP are) (NP (BASENP (DT the) (NN sort)) (PP (IN of) (NP (BASENP (NNS studies)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBP confuse) (BASENP (NNS parents))) (PP (IN on) (SBAR (WHADVP (WRB how)) (S (VP (TO to) (VP (VB raise) (BASENP (PRPD their) (NNS kids))))))))))))))) (PERIOD .))