Lì / shǐ / kè / shàng / lǎo / shī / jiè / shào / le / Kè / lǐ / mù / Zhàn / zhēng / de / bèi / jǐng历史课上,老师介绍了克里木战争的背景。In history class, the teacher introduced the background of the Crimean War.