lesson

/ˈlɛsən/

a unit of instruction

Chinese meaning: 课；教训

The history lesson today focused on the causes of World War I.

今天的历史课重点讲第一次世界大战的起因。

Failing the exam taught him a valuable lesson about the importance of preparation.

考试不及格给他上了宝贵的一课，让他认识到准备的重要性。