One of the characteristics ——主语
of the Sinitic languages ——介词短语作后置定语
to which Chinese belongs ——定语从句(先行词是one of the characteristics)
is ——谓语(系词)
that a relatively high percentage of their words are monosyllables ——宾语从句(从句内部成分分析略)
句子的主干用加粗字体标出。
《高考英语备考1号·速效编》
《高考英语备考1号·写作编》
《高中英语晨读晚记》
《高中英语错题笔记》
《零起点考大学英语》