lì / shǐ / kè / shàng / lǎo / shī / jiǎng / jiě / le / é / luó / sī / dì / guó / de / kuò / zhāng / guò / chéng历史课上,老师讲解了俄罗斯帝国的扩张过程。In history class, the teacher explained the expansion of the Russian Empire.