为给定的英文句子手动标注POS（Part of Speech），并用其创建一个句法结构树，然后输出树的字符串表示。
This is a sample sentence that we will use to demonstrate how to tag parts of speech and create a syntax tree.
This/DT is/VBZ a/DT sample/JJ sentence/NN that/WDT we/PRP will/MD use/VB to/TO demonstrate/VB how/WRB to/TO tag/VB parts/NNS of/IN speech/NN and/CC create/VB a/DT syntax/NN tree/NN ./.
(S
  (NP (DT This))
  (VP (VBZ is)
    (NP (DT a) (JJ sample) (NN sentence))
    (SBAR (IN that)
      (S
        (NP (WDT we))
        (VP (MD will)
          (VP (VB use)
            (S
              (VP (TO to)
                (VP (VB demonstrate)
                  (SBAR (WRB how)
                    (S
                      (S
                        (VP (TO to)
                          (VP (VB tag)
                            (NP (NNS parts))
                            (PP (IN of)
                              (NP (NN speech)))))
                      (CC and)
                      (S
                        (VP (VB create)
                          (NP (DT a) (NN syntax) (NN tree)))))))))))))
  (. .))