Lì / shǐ / kè / shàng / lǎo / shī / xiáng / xì / jiǎng / jiě / le / Shí / zì / jūn / Dōng / zhēng / de / bèi / jǐng / hé / yǐng / xiǎng

历史课上，老师详细讲解了十字军东征的背景和影响。

In history class, the teacher explained in detail the background and impact of the Crusades.