%%%------------------------------------------------------------------------------------------------------------
%%%  tree binarization
\begin{center}
\begin{tikzpicture}

{
{\small
\begin{scope}[sibling distance=4pt, level distance=25pt]

{\footnotesize
\Tree[.\node(n1){NP};
     	[.NNP \node(sw1){美国}; ]
     	[.NN \node(sw2){总统}; ]
        [.NN \node(sw3){乔治}; ]
        [.NN \node(sw4){华盛顿}; ]
     ]
}

\node [anchor=north] (tw1) at ([yshift=-2em]sw1.south) {U.S.};
\node [anchor=north] (tw2) at ([yshift=-2em]sw2.south) {President};
\node [anchor=north] (tw3) at ([yshift=-2em,xshift=1.5em]sw3.south) {Washington};

\draw [-,dashed] (sw1.south) -- (tw1.north);
\draw [-,dashed] (sw2.south) -- (tw2.north);
\draw [-,dashed] (sw3.south) -- (tw3.north);
\draw [-,dashed] (sw4.south) -- (tw3.north);

\node [anchor=west] (rulelabel1) at ([xshift=1in,yshift=0.3em]n1.east) {{抽取到的规则：}};
\node [anchor=north west] (rule1) at (rulelabel1.south west) {NP(NNP$_1$ NN$_2$ NN(乔治) NN(华盛顿))};
\node [anchor=north west] (rule1t) at ([yshift=0.2em]rule1.south west) {$\to$ NNP$_1$ NN$_2$ Trump};
\node [anchor=north west] (rule2) at (rule1t.south west) {NP(NNP$_1$ NN(总统) NN(乔治) NN(华盛顿))};
\node [anchor=north west] (rule2t) at ([yshift=0.2em]rule2.south west) {$\to$ NNP$_1$ President Trump};
\node [anchor=north west] (rulelabel2) at ([yshift=-0.3em]rule2t.south west) {{{\red{不能}}抽取到的规则：}};
\node [anchor=north west] (rule3) at (rulelabel2.south west) {NP(NN(乔治) NN(华盛顿)) $\to$ Trump};

\end{scope}
}
}

\end{tikzpicture}
\end{center}