lǎo shī / jǔ lì / shuō míng / shén me / shì / zhí yán mìng tí / bǐ rú / suǒ yǒu / niǎo / dōu huì / fēi

老师举例说明什么是直言命题，比如“所有鸟都会飞”。

The teacher gave examples to explain what a categorical proposition is, such as "All birds can fly".