zhè / zhī / bù / duì / zài / shān / chéng / lǐ / kùn / shǒu / le / sān / gè / yuè / zuì / hòu / zhōng / yú / děng / lái / le / yuán / jūn

这支部队在山城里困守了三个月，最后终于等来了援军。

The troops held out in the mountain city for three months and finally received reinforcements.