sententious

他那番关于道德的说教听起来既虚伪又自以为是。

His ___sententious lecture on morality sounded both hypocritical and self-important.

老师那充满说教的演讲让学生们昏昏欲睡。

The teacher's ___sententious lecture made the students drowsy with excessive moralizing.

他用一句简洁有力的话结束了演讲，带着明显的说教意味。

He concluded his speech with a ___sententious remark that carried clear moral undertones.