(S (S (SBAR (SINV (SINV (VP (MD Should)) (NP (BASENP (JJR more)) (PP (IN of) (BASENP (DT the) (NNS sensors))))) (VP (VB fail)))) (COMMA ,) (S (BASENP (DT the) (NN engine)) (VP (MD might) (VP (VP (VB burn) (PRT (RP out))) (PP (JJ due) (PP (TO to) (NP (NP (BASENP (NN lack)) (PP (IN of) (BASENP (NN fuel)))) (COMMA ,) (NP (BASENP (DT a) (NN situation)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBZ has) (RB not)) (VP (VBN been) (VP (VBN tested)))))))))))))) (PERIOD .))