xiàn shàng zhǎn shì qián，lǎo shī cháng shuō：“méi yǒu fā yán de tóng xué qǐng xiān jìng yīn”

线上展示前，老师常说：“没有发言的同学请先静音。

Before an online presentation, the teacher often says: 'Students who haven't spoken, please mute yourselves.'