lì / shǐ / kè / shàng / lǎo / shī / jiè / shào / le / Yē / lǜ / Dà / shí / jiàn / lì / Xī / Liáo / de / jīng / guò

历史课上，老师介绍了耶律大石建立西辽的经过。

In history class, the teacher described how Yelü Dashi founded Western Liao.