Lì / shǐ / kè / shàng / lǎo / shī / jiè / shào / le / Bō / cí / tǎn / huì / yì / de / bèi / jǐng

历史课上，老师介绍了波茨坦会议的背景。

In history class, the teacher introduced the background of the Potsdam Conference.