gǔ / dài / shān / qū / cháng / yǒu / shān / zéi / chū / mò / shāng / duì / bì / xū / jié / bàn / ér / xíng

古代山区常有山贼出没，商队必须结伴而行。

In ancient times, bandits often lurked in mountainous areas, so trade caravans had to travel in groups.