All mobile phone and beeper must be switched off during lesson.

学员在上课期间必须将手提电话及传呼机关掉。

youdao

She hadn't been attending during the lesson.

上课时她一直不专心。

《牛津词典》

His sailing instructor fell overboard and nearly drowned during a lesson.

他的帆船教练在一次课上落水，差点溺死。

《柯林斯英汉双解大词典》

504-- this whole course, is about this transformation, as I mentioned during the first lesson.

504这门课程的重点，是关于转变，正如我在第一课中提到的。

哈佛公开课 - 幸福课课程节选

One professor, for example, tested whether showing his face during a lesson led to improved learning.

FORBES: Why Don't Entrepreneurs And Learning Scientists Talk Much?

Peter Harvey, 51, was provoked by pupils during a lesson in July 2009 when they called him a "psycho".

BBC: Peter Harvey

Example: Every student pilot learns how to read an altimeter during the first lesson.

FORBES: My Ken Lay