\begin{theindex}

  \item du
    \subitem 段誉, \hyperpage{5}

  \indexspace

  \item qi
    \subitem 乔峰, \hyperpage{5}

  \indexspace

  \item shu
    \subitem 树结构折筷过程, \hyperpage{5}

  \indexspace

  \item ti
    \subitem 体细胞拷贝数变异, \hyperpage{5}

\end{theindex}