(S (S (PP (BASENP (NN Two) (NNS weeks)) (PP (IN before) (NP (BASENP (DT the) (VBN failed) (NNS attacks)) (PP (IN of) (BASENP (NNP July) (NN 21)))))) (COMMA ,) (S (NP (BASENP (DT a) (NN series)) (PP (IN of) (NP (BASENP (NNS bombs)) (PP (IN on) (BASENP (NNP July) (NN 7)))))) (VP (VBD killed) (NP (BASENP (NN 56) (NNS people)) (COMMA ,) (PP (VBG including) (BASENP (NN four) (NN suicide) (NNS bombers))))))) (PERIOD .))